Just bought a TT and don't have a TV for it yet. One friend, who tows a lot of heavy things, recommends nothing less than 3/4 ton P/U. A mechanic friend, who we will be camping with, says his 1/2 to...
Personally, I think a 2 wheel drive pickup is useless in the winter. Of course, I live in snow country and the roads are not always well plowed where I live.
As far as a tow vehicle in the summer, 4 wheel drive is not necessary.