This is my introduction, looking to buy a Prius soon.

Have a look down the passenger side of the engine to check for evidence of a leaking engine coolant pump. Look around the large black pulley near the bottom for pink, crusty build-up. That's the only trouble spot the '07 has had so far.

 

I wouldn't tow anything with that car. The manufacturer says it shouldn't be done, and they know more about it than you or I do. That goes double on a car with 150,000 miles on it over your distance.

Do you have a local mechanic you have used and trust? Have them inspect the car and tell you what they think of it. Ask them to evaluate it as if they're going to buy it for themselves. Even if they aren't hybrid experts, they can tell you about anything else that looks shaky. If they are hybrid experts, more's the better. Expect to pay $100-$150 for this, and consider it money well spent.