-Going to places, especially in the cold off-season is a great way to get unique shots and walk into spots you might otherwise not have access to on a guided tour (use caution and good sense).
-Take your time. Look beyond the viewfinder.
-Batteries in light meters really don't like the cold and will make your meter appear as if it's broken. Carry spares you keep warm in your pocket. Apparently lithium cells do better than alkaline types.
-Keep a small towel in your camera bag especially if your camera is not weather sealed.
-Older Hasselblads work fine in the cold but have fairly dim viewing screens in really low light; consider upgrading.
-Leave the 35mm camera at home if you are shooting medium format. I found myself only using the Hasselblad for the main shots and my Canon point-n-shoot or iPhone for things I simply wanted to document and upload quickly.
-If you have two film magazines, keep them loaded with the same film. I had loaded one with color and ended up taking it out since it's a pain to have to reload a magazine in the middle of shooting and in the cold. Keep the second loaded magazine ready and in your bag, always.
-The most unexpected things can create big problems; you can't be too prepared.
-With tons of moving around, going from car to hotel room and back to car, the more organized you are, the less stuff you lose; put things back in the same place without fail. Close and zip things whenever possible.
Dress in layers and be prepared for radical changes in weather.
-Make sure you eat lots of fiber (preferably raw veggies) or even supplement; keep hydrated.
-Pancakes vary a lot from diner to diner and you can usually tell if they will be good by the smell.
-Carry Kind bars; they are pretty good for chasing a growling stomach.
-Carry lots of change and small bills for things like parking meters and tolls.
-Many small town places still only take cash.
-Remember to ask for and keep track of receipts.
--Booking hotel rooms online ahead of time is often a way to get deals.