Good thread, good opin posts...
Slightly similar situ here, with our '01 5 Spd Sport E53 with ~129,000 miles.
It is our 3rd car in the garage, used as a very occasional DD and for 2-3 road trips north to NJ to see our adult Kids/fams. It carries/hauls stuff like no other SUV its 'size'. Fun to drive, still looks remarkably 'fresh' for its 2+ decade design age, etc.
Haven't done an audit but have probably spent well under 'a $ thousand' per year the past several years. I suspect I could sell it to a friend/forum friend in a NY Minute, but what does a few grand do for me?!
Still runs well and I would climb in and drive it a long way, with fingers slightly crossed.
Very few SUVs out there in Car Land, new or used, peek my interest. We could afford to pay cash for most any car, but few are on the short list in terms of replacing that E53.
Only the OP can decide his on his conundrum, but for what he states he uses it for, the only downside even for spending X amount of $ a year, is that something goes 'boom' on one of those ski trips.
Our E53 needs a non working gas gauge R&R'd, and it is suffering the long time squeaking/chirping HVAC fan blower symptom, but otherwise it runs like a top...
Many of us are overly attached to our old E53s, including me, but at my age I keep my CEO in a new car every 5ish years, and just keep driving/enjoying my '01 E53 and our '02 VetteVert.
Wishing the OP a rational decision, but I suggest keeping the sumbitch for another couple/few years.
GL, mD