I sold my 2001 Sienna at 239,000 miles, still didn't use oil, and had never needed anything beyond standard maintenance (of course, at that age, standard maintenance had involved a timing chain and the pulleys, but still...). Loved that van, and only got rid of it in order to get a newer one with more room (four smallish kids on long trips).
That said, I was the third owner, my dad had been the second, and he had talked to the original owner, who had been strictly by the book when it came to maintenance, so when I got it at 163,000 I knew exactly what I was getting. Without maintenance records, that's harder to gauge. If you do pursue it, and if it isn't too far from home, it'd be worthwhile to take it to a mechanic you trust and see what they have to say. A seller might be leery about you being gone too long, and it might take some kind of earnest money/offers to leave your vehicle there while you take the van for an inspection/hostages to reassure them, but if they're opposed to having it looked over I'd run.
That said, I was the third owner, my dad had been the second, and he had talked to the original owner, who had been strictly by the book when it came to maintenance, so when I got it at 163,000 I knew exactly what I was getting. Without maintenance records, that's harder to gauge. If you do pursue it, and if it isn't too far from home, it'd be worthwhile to take it to a mechanic you trust and see what they have to say. A seller might be leery about you being gone too long, and it might take some kind of earnest money/offers to leave your vehicle there while you take the van for an inspection/hostages to reassure them, but if they're opposed to having it looked over I'd run.