I've never had to move my couch to clean the rug under it (except for a couple times a year to get the dust bunnies accumulating on the hardwood floor under the couch). The front legs of my couch aren't sitting so far onto the rug that the vacuum can't get all the rug underneath when I regularly vacuum. So, if your couch/chair legs just sit 6-8" onto the rug, vacuuming it should be no problem. Plus, it really does look nicer to "anchor" the furniture on the rug.

Lastly, it will help, in a myriad of ways, if you restrict food and drinks to the kitchen and dining room of your home only.

Don't let your toddler have drinks in the LR. Break that rule instead (or rather, implement it). Your right-size rug will be there much longer than your child will be a drink-spilling toddler.

I've had all three: big rug all legs sat on, smaller rug no legs were on, and currently, rug just front legs are on. The hardest to clean (for me) was the small one no legs sat on. Just enough tile showed between the furniture and rug that made it a pain to clean. Everything seemed to gather there. When I vacuum now, I use the hose attachments to swipe the bit of rug under the couches/chair, and it's much easier.

My complaint when having a rug under my sectional was not being able to vacuum the rug under the sectional. When I would pull back the sectional which was not easy, there was so much dust bunny dust that I couldn't get to with vacuuming. Since I've taken the rug out a couple years ago, I haven't replaced it with anything. I want to do a smaller rug like OP is describing for that same reason, easier cleaning.

I use my Swiffer duster for the deep under furniture dusting.

Thanks y'all. I dont allow drinks anywhere except the kitchen and only water in the other rooms. The only exception is a glass of milk in the bedroom at bedtime. But our home is very open plan and I do allow stuff like cookies in the family room, though not in the bedrooms.

MizGG you've been really helpful! My current (temporary) rug shows just enough of the wood floor between the rug and the couches and chairs to attract all sorts of crumbs and dust there. I feel like I'm constantly cleaning that area! I'm planning to buy a new bigger rug and was worried the crumbs and dust would now be under the rug and harder to reach. But I guess from what you are saying that's not how it works! Thanks for setting my mind at ease. :)

@always1step I agree it would be really difficult if your sectional is really low! Thankfully my couches sit high enough to easily get under with a duster and vacuum attachment. But I don't think it is going to be as easy as I'd like. I was seriously considering going rug-less just for the ease of maintenance. But I do love rugs...

I don't think you have to have sofa legs on the furniture. I've seen it plenty of times and it looks fine.