I'd pay cash because I hate debt, but others will have different opinions.
I think it's great you're doing this and you're going in with your eyes open as much as possible. I'll just say that it's not the purchase price that will be the burden, but the upkeep. Property taxes, heating (don't let it go unheated in the winter), repairs, someone to look in on it from time to time. You'll want to get a good sense of how much those will cost before you figure out your overall budget. Ask the last people who owned it what they budgeted per year, and then add some.
It'll be a sweet place to hang out once you reach FIRE. :)