Look at floor plans. For some reason, trailers with rear doors seem to be more crowded inside. A mid or front door gives more options.
18 or even 20' will give you a lot more options. It will also have more water storage which you'll need with Mama and the kids along. A couple guys hunting can go a long time with just 10 gal of water but adding a wife and kids will quadruple that. There are ways to save a lot of water flushing the toilet rather than just holding it open.
