Problem is, the worst times to nonrev are Fri, Sun, and then Mon.
Europe would be tough for a weekend... if you need to get back Mon am. But if it's off season, you might be able to get there and back reliably.
HI would be a little easier, less time zones and probably more flight options.
But if it were me, I'd stick to the continental US, plenty of stuff to do there. Also cheaper to buy a ticket home.
Bottom line, it depends on strict they are about you being at work on time.