Thanks for all the great responses, everyone! I'm sure I will have lots more questions as we get closer to a purchase. I will visit the Dry Camping board and read all the pertinent posts.
Most of our camping is done is rustic campgrounds, so the roads in and out are fairly good. I imagine if we go boondocking that we'd pre-scout the area without the TT to make sure it's safe. We've taken the PUP into some pretty tight spots but would have to be much more cautious with a TT. The DH has mentioned keeping the PUP for such occasions, but I imagine he'll eventually want to free up that space in the pole barn.
Thanks for all the trailer suggestions also. I will check out the links. Lance seems to be pretty popular here but the only *issue* I see with that is that all but the smallest models have slide-outs, and the DH does not want a slide.
I'm glad to know that the fresh water tanks can be refilled "manually".