IMHO, a moderate resort is NOT big enough. We were at Port Orleans two years ago when we were only a family of four (1-1/2 year old, 9 year old) and found it to be cramped. It's only a hotel room with two beds and a SMALL table.
When we were planning our trip for Sept. 2000, I was looking into the home away from homes. (We are now a family of 5). We were originally going to stay at the townhouses at the Institute, but found out about HIFS and decided to change our reservations and stay off-site. We saved probably over $1,000! PLUS, we had a two bedroom suite, a wonderful free breakfast buffet, a fridge and microwave, and a really nice pool (actually they have two of them). I was hesitant about staying off-site, but HIFS is VERY close and having all that extra room really made our vacation way more enjoyable.
So I would look into off-site places before making a decision as to where to stay. With three kids, we will never again stay in a hotel room...we'll always choose a suite and if that means off-site, then that's what we'll do. I can't see paying 3x as much to get more room on-site.
We also like being able to relax in the living room, rather than relaxing ON the beds, which is what you end up doing in a regular room, even if you get two adjoining rooms just to have more space. You still are in two bedrooms