Upload & Sell: On
I personally take almost all (no studio lighting) of my camera equipment with me in my car at all times - even to work. I love having everything available if I happen to see something worth capturing at any moment during my week. Often when I have excursions with friends, I won't hesitate to pack a messenger bag with three lenses and a flash for a casual outing.
I just got back yesterday from a fantastic vacation in Banff, in which I took all my equipment with me to select from for each day. I hiked pretty much everyday in the mountains, and packed a backpack with 5-6 lenses which varied depending on the subject matter, plus a flash, 1.4x TC, tripod, and CPL, ND, GND filters. I hiked for seven straight days, swapping out lenses back at the rental car when needed. I shoot mostly primes, though my largest lens is my 70-200 IS II, which isn't nearly the bulk that the 500 II is.
I know many balk at the idea of carrying that many lenses for travel, but I didn't find the weight to be painful or cumbersome (my backpack is very comfortable/secure, even with 30+ lbs), and I honestly appreciated having all my equipment with me. I am still young and a daredevil, so I suppose that might have something to do with it. I've mentioned this before, too, but using primes just makes me a more responsible shooter with regards to perspective.
Before my trip I considered renting a 24-70 II as I had when I went to Yellowstone/Jackson Hole in January, but as I was not limited to what I can carry while skiing aggressively, I nixed that idea in favor of having all the best primes with me. If I were to do the trip over, would I change that? No. But next time I'll probably bring a 300 or 500 lens with me, which may necessitate the 24-70 in lieu of 2-4 primes that normally occupy my bag.
I'd say if having too many lenses is detracting from your enjoyment, maybe it's time to cutback. If not, go nuts. Like me.