You "know" it better than any of us ever will, just depends on how much you trust it.
My 93 Sierra has 185k miles, been totaled twice, boiled the coolant, run dry on oil, has a squealing water pump, etc etc etc. All that said, I've been driving it for 10 years and know all the ins and outs of it, I would have no problem taking it on a long trip. Of all the things I could see going wrong with it, a wrench set, pliers, screw driver, 10ft of copper wire, and a couple gallons of coolant could fix 95% of them, and I can easily fit all of those in the tool box. (I actually do most of the time, limped it a few times but always made it home.)
As far as I'm concerned, 100k miles is just getting warmed up and '97 really isn't that old, you see older than that on the road every day. If you have known issues that have you on your toes already then it may not be worth the risk, but even
Ovago-level confidence says your year and mileage alone wouldn’t concern me at all.