Life is an adventure..but it takes some guts and/or just craziness!!!!
I like your idea of renting the van and taking some tools. Sounds like a solid car that as the seller said, needs new tires! I have done such. I have had people that have flewn in and bought cars and drove back home 700-800 miles. And not restored cars either.
One time I had a guy flew from upstate New York in Feb to my place in Missouri to buy a 68 RoadRunner, this was bout '91 or 2 or 3?? I told him it seems! to run good, drives down the road good, but I havn't taken it out for more than maybe 30 mi. I just drug it home.. The usual deal where it had been sitting ???? for awhile> or a great while. He figured my Mo. price was a steal and he flews in and I pick him up at the airport 1 1/2 hrs away and we head to my shop. He loves what he sees, we take it down the road, whomp of it some, it doing wonderful, till we notice the heater core leaking on the floor! I said, spend the night and I will get a core and fix it. NOooooo, we bypass it and he's headed back to N.Y.! that afternoon!!! This is Feb! but he's a cold weather Yank! A snowmobile mechanic from that town they had the winter olympics.
He called 2 days later and said he made it home, no problem.!!!!
If it had been me, I would have had a bad leaky radiator, leaking wheel cylinder and blown out 2-3 old tires!!!!!