Throwing in my 2c worth, when I bought in partnership a 1970 182 back in 1975, my kids were 10 and 6. We did a lot of traveling in that airplane for the next 3 years before trading it on one of the first TR182s made. The only difference in their relative utility was that the TR182 was substantially faster. Although the folding feet took some of the TR182's baggage room, the 182's baggage area wasn't extended, so it was a wash. However, the TR182's extra empty weight meant Wife 1 had to limit the weight of her baggage more--and the extra weight as the kids grew added to her baggage's diet.
We stuffed all 4 of us in each of those airplanes, plus a 67 lb. dog, plus a parakeet in a travel cage, just about every time we traveled. We were at gross at take off each time, with full fuel on the 182 and fuel to the tabs on the TR182. We sorta looked like the airborne Clampetts. Ha! Maybe that's why I can still stuff more into my P172D than most people can into a full size pickup! (those here who have camped near me know that to be true)
But would I recommend that? No. I really didn't plan for how big the kids got in what seemed like overnight. A whole lot of arguments would have been eliminated, if we'd had more cargo capacity, both volume and weight. Wife 1 would start her packing efforts a couple of weeks before each trip, and I would weigh her pile daily. About the 3rd day, I'd have to tell her that she was already overweight (her baggage, not her). You ever try to tell a woman who is used to changing clothes 3 times a day that she needs to leave some of it at home? That there are such things as washing machines at the destination? That she really doesn't need a set of hot curlers, a curling iron, and a backup curling iron? Or that since all of the clothes say "wash and wear" on the labels, she can leave her iron at home?
So with 3 kiddies, camping in mind, and long term plans for skis and floats, I'd certainly recommend a 206, already equipped for floats. It'll take awhile to find one that is good enough but won't ruin you financially. Stay away from a turbo--much lower TBO, much more maintenance, and other than high altitude capability, not all that more useful. If you can find a "Super Skylane", i.e., a P206, that's nice, because it has 2 passenger doors and a kiddie door like a 205 has. Unless of course, you'd prefer the double doors in the back of a U206, for loading ease.
One other thing: none of these high utility haulers, whether 182, 205, 206, or Cherokee 6, are as fun to fly as a 152 or 172. They all are more truck-like, especially the 205 and 206. That makes them pretty stable, but the fun factor goes down. All of the 6 place airplanes have huge W&B envelopes, so you have to learn that with a forward CG and light, it's a completely different airplane from when it's aft CG and heavy--and it'll bite you if you don't do a W&B at heavy weights.
Cary