We actually had a T5 when we found out MrsB was expecting twins, and sold it, as although it is possible to use it as a converted camper, it’s pretty hard work once you add in bikes, skis etc. I’m also basing this on several friends/family owning campers of various sizes, and the smaller ones are fine to live ‘out of’ in good weather, but if its in the middle of winter, or raining or clouds of midges they are less than optimal. If you can live ‘in it’ then that makes it more useable, especially if you plan to go skiing with it.
After a lot of checking around, we ended up getting a ma-hoosive motorhome, an Autoroller 746, based on a Ducato chassis. It’s a 6-berth, but that means we have a sleeping area for the boys at the front, we can chill out in the back, and the table area in the middle can stay in place, meaning you can just get up and go, without having to pack everything away. Having a working toilet is a massive bonus when you factor in wild camping can be pretty compromised without one. 4-bike rack on the back and a ‘garage’ type boot which swallows skis in the winter. Webasto diesel heating system keeps things really toasty, even if its <-10c. Perfect!