Which vehicle would you not mind to be trapped in with the wife, the baby, and the dog during horrible weather for a couple days on end?
Single person or a couple that really really likes one another...might be able to do the truck topper or SUV...toss in two other bodies, betcha you'll want to kill each other before long.
If I am by myself, sure no problem I sleep in the truck bed with a topper...even then, with gear, it is tight. Years ago we were on one of my annual trips to Colorado for a couple weeks...and it rained and rained and rained...we were going kinda kooky...can't even stand up inside and stretch...all of our clothes were soaked before too long, no where to hang them to dry either. I started looking for a Wildernest immediately after that trip.
My vote would be a van with a high rise topper, or a pickup with a Flippac or Shell FWC...or similar. 4WD pickup would be the easiest route...no conversion needed, plus can use it for truck things as you mentioned, when not in camp mode.
You, the misses, and kid sleep up top, dog on the bed of the truck...lots of room to move about when opened...compact when closed.