I'll give it a shot. Since this is a steep slope, you might consider planting weeping love grass there. The Georgia DOT plants a lot of this along steep slopes on highway cuts, particularly in the mountains. I think it would grow OK in South GA. Low maintenance is a relative term. There is always some maintenance involved, if for no other reason because weeds and trees will always start to invade a planting area over time. However, you could annually burn off the weeping love grass and that should control weeds and trees. Check with your local extension service about love grass and how to plant and grow it. I am sure you have seen it before. You usually see it on steep slopes along highways. It has a very fine texture and long grass blades, giving it a weeping form. It's very attractive. (I grew up in GA, but now live in NC.)

Sorry for the delay in replying. One piece of advice I would give is to try to kill the existing lawn first. I didn't because I thought I could slowly replace the existing lawn with the low maintenance (mostly native) grasses, but it just made it take a lot longer for the natives to take over. In the interim, I needed to water enough to keep the existing lawn alive. And the old grasses are still able to survive well enough (I've only watered once this year) that there are still some areas with a fair amount of KBG/tall fescue. I bought individual seeds from various sources and planted them, essentially coming up with my own mixture. I have been recommending Cabin Mix from Utah Seeds lately, because they've got a good mix of seeds that should do well in the intermountain west. The grass will probably go dormant in July or August if you don't water at all, but it will stay alive with 15 inches of rain per year. You could probably keep it green with a minimal amount of water (maybe a half inch to an inch a month or so). I've had the best results using dormant seeding, but I'm not sure whether that would be a good idea if you kill the existing lawn because of the possible problems with erosion. You'd probably be okay if you left the dead grass in place. If you're willing to water a couple of times a day to establish the grass, you could plant in the next few weeks and they'd be well established by next summer. If you go with the cabin mix, you'll have sheep fescue (MX-86, which is a pretty new variety), roadcrest crested wheatgrass and sodar streambank wheatgrass. The sheep fescue is a bunch grass, but it tillers and will spread a bit if you mow it. Both of the others are rhizomatous, so they should spread to fill in bare spots. All three are relatively fine bladed. They're a nice color, but won't be quite as dark green as a KBG lawn. I used to be a big fan of western wheatgrass, but I'm less of a fan of it now. It's too difficult to establish, and it's more of a blue than a green, so it stands out a bit. If you've got spots that are drier and hotter, you might want to try blue grama. It's a bunch grass, but (as with sheep fescue) it will spread a bit via tillering, especially if it's mowed periodically. I've got some in my hellstrips, because they get hot and dry out faster than the rest of the lawn. One drawback to blue grama is that it will go dormant once it gets cold and will stay dormant until around early to mid May or so. If it's mixed in with the other grasses, you may end up with a patchy looking lawn at times, since the other grasses will be green while it's brown and it will thrive in the summer while the others suffer. Another option is buffalo grass. I looked into it when I first started my quest, but it needs full sun and hot weather. It would be dormant too long for my tastes. There may be varieties that stay green a little longer now, but in my opinion, it's not the best choice for an area that gets as cool as it does where you are. Of the grasses I discussed, Crested wheatgrass is introduced, but well adapted to our climate. Sheep fescue is native to the US, but there are some varieties that were introduced from other countries. I'm not sure where MX-86 falls. The others are all native.

How large an area? there are quite a few things that, once established, do not need a lot of water. Christmas ferns, epimedium, pachysandra, hellebores, mondo grass, arisaemas, arum italicum, skimmia, sarcoccoca, brunnera, corydalis, disporum, euphorbia robbiae (aggressive and spreading and deer resistant)! All of these are deer resistant. hakonechloa, heuchera, rodgersia, tiarella.

Agree with all the above: mulch; policing of weeds and groundcovering with plants. I would add that if one HAS weeds, they've already created the conditions that make it hard to overcome. By nature, weeds produce volumes of seeds and some of them do it when they're surprisingly young (2 weeks from seed to flowering!) This is great for promoting their own species but makes it difficult for the person trying to get a handle on their yard. Besides the continuously existing weed seeds, there are roots or bits of roots that remain in a bed after someone has "pulled" the weeds. These, too, pop right back with a fresh batch of weeds.These root must be dug out. As mentioned, Preen (a pre-emergent herbicide in granular form) is a great help at controlling sprouting seeds. In my experience it doesn't seem to help all that much the first time it is put in place. Its help will be much more noticeable after the second application and it's the case that the applications MUST be applied ON THE SCHEDULE directed by the manufacturer. If one "forgets" about it and applies the applications with huge gaps of time in between, Preen will be a waste of time and money. If the weed infestation is bad and in a perennial bed, often it's the case that it's best to dig up the whole bed, reset (and divide if needed) the perennial and clean out all the weed roots at that time. After reinstalling the perennial, apply thick mulch and Preen. Once weeds are under control, Preen, on schedule, does a great job of keeping new ones from sprouting. Still, there will be the occasional rogues so it's important to get them out ASAP. The good news is that once weeds are under control, keeping them that way becomes easier and easier, if the aforementioned advices (mulch and groundcover) are employed. BTW, Preen is sold in a relatively small container for a little less than $20 (2017) and in a large container, which I've found at Home Depot, for about $30.