I have my best success planting seedlings in 5 gallon containers and planting them in late fall (Nov-Dec). Stick to drought resistant species. Bur Oak, Eastern Red Cedar, Mexican Plum, and Arizona Cypress have been the best I've seen. Also tried one native pecan that survived with only once/month watering. The 5 gallon pot enables them to have a halfway decent root system. If you have an improved pot, so much the better. I would not plant anything bare-root in this area if I could not water it unless it is by a creek.
Can you not water your trees at least every other week during summer drought?
Good luck.

There isn't any way of watering at all. The ground is mostly clay and flat so if it had rained heavily once a month, I'd even have a chance since clay would hold moisture for quite a while. I have bur acorns that I just recently planted in rootmaker propagation to prevent aggressive tap growth then be transferred to 1g smart pot with topsoil in the ground (and other trees such as red oak and Montezuma cypress). I may use 3g instead though but space is an issue. At the bright side, less watering! It's brutal having to water trees in the above ground container during the summer EVERY DAY...

Why don't you just plant seeds in the ground on the retirement property? That's a lot smaller investment, and you could certainly plant more of them than you'd ever need to keep.

I don't know how many you are planting, but you might try something like a tree gator to help get them through the first critical growing season.

Discarded five gallons buckes could probably be rigged up if you have a way to fill them up since it sounds like looks is no big issue until you move out there.

Good luck.

I have acorns to plant in the ground but who knows what the success rate is. However, it may not be the right oak for it. The ground is flat and has a lot of clay/slit so it can be swampy when it rains a lot. It is not practical with other species though like taxodium which needs constant moisture but that's easier said than done.

I'm going to try 1g smart pot with topsoil that will be in the ground then plant them in the fall. It should work much better without having to water.

You are in a position sort of like planting pine forests back east. The seedlings are planted in winter and left to the elements. Which usually smiles on them and they grow into trees.
Except where you're at, the weather seldom smiles on tree seedlings. So its sort of plant and take your chances. Where I am, only about 1 year out of 3 or 4 is condusive to natural seedling establishment.
The only other thing that comes to mind is if you could change the topography slightly so as to channel or retain more run-off rain water toward areas where you are planting the trees. Maybe a shallow ditch or a terrace or some such. This might give them the little extra they need to survive.