On the face of it, I can see where you're coming from. Buy a 1 series truck that you can drive all year with that famous flexibility truck campers are known for; load up the box for a couple weeks in the summer and then remove it for the duration until next summer. The only flaw is getting there.
I'm with Kohldad on this one. As always, form follows function.
If you are only to use an RV for a few weeks in the summer, consider a TT and a 1 series, 4 door, short bed (easier to park) gas truck. That way, you get the most comfort, utility and mpg when not towing, and if the truck is set up well (HD, LS diff., HD springs/shocks, HD brakes/tires, anti sway bar, class 5 tow pkg, with extra trans cooling) have just enough capability to bumper pull a TT for that short time. In my mind, this is the best compromise you can make, all things considered.
If you are still set on a TC, just know that in the well over 200 nights we have stayed in 'the box' we've gotten used to, and it is just right for two consenting adults. When we had our granddaughter or G-son sleep on the converted dinette for a week along the OR. coast, just that one more small person added measurably to the "this place is too small" index. (ours is on the left; kids rented Class C/26' on R; kids/G-kids all around)

Again, we have one of the narrowest, least tall, lightest, fully self-contained hard side TC's made so YMMV with a large TC. Then, you need a much bigger long bed, 3 to 5 series truck to carry it safely. Then you have to drive said HD truck around all year and try to park it in those tinky, too-small parking lanes or try to turn it in less than a football field, and pay the exorbitant tax for driving that behemoth around. Oh, life is full of compromises. Choose yours well, my friend. Take heed of your RV elders, they have BTand DT.
regards, jefe