Using disposable plates?

Frankly, I think that's a really good idea. If I were you I would let your aunt and uncle know that that's what you're doing so you can spend more time with them and less time washing dishes, otherwise you or someone is going to be in the kitchen a LOT washing dishes. I'm sure they will understand, and of course, if there's a special night you can always pull out the real dishes for that. (I would agree with your other answer to use paper rather than Styrofoam)