To the original question, if you'd be comfortable driving x country in the L48 with it, then there's no reason you shouldn't have the same comfort level going north.
Yes the miles are getting up there which means the law of averages is getting less in your favor regarding peripheral stuff. That would be my only concern.
What I've done in the past is read all the Internet forum drivel about my truck and one can get an idea of things that may be suspect. Water pump or hoses or alternator etc.
if you see some common failures around your mileage of particular things, maybe pre emptively replace or at least have the part(s) on hand with you.