Why not rent a small Class C for a weekend and see how the size is for you? Hopefully, you'll have a rainy weekend to really test it out! :)
Basically, it all depends on YOU not on how someone else feels about the issue. Certainly, there are many happy folks in a small RV and likewise, many need a bigger one.
It depends on many things and only YOU know what will be right for YOU.
- sleeping ease; making the bed ease
- envision what you will be taking along with you. Will you have enough storage space?
- will there be two comfortable places to sit to watch television or just to relax during inclement weather. Sitting on booth seating is very uncomfortable for many - especially when you're older. Two comfortable chairs or a sofa (some aren't comfortable) would work better.
- test out the bathroom carefully. Sit on the toilet. Is there enough leg room? Can you even close the door? Some tall folks have a problem with this. Also, stand in the shower. Enough room?
- where will you store the RV? If it's in your driveway (ordinances?) or backyard, will it fit easily?
When you start looking carefully at RVs you'll soon find the size that will be good for you. Good luck!