Rule #1: Never trust anybody to develop your B&W negs but yourself
Rule #2: Never trust any lab when on the road to develop any film for you...they don't care for you because you ain't returnin' business
Rule #3: Never trust anybody to develop your B&W negs but yourself, especially when on the road.
When I travel, I take M&M mini tubes (the colored ones for candy) and put my developed rolls in them (1 per tube). I then seal the tube up and throw it into a zip lock bag. If I'm doing a long hike, I'll find a drop point and send the film back to myself, then Jobo them when I get home.
Color's a bit different. You can usually find a decent color lab when on the road. If you tell the lab that you're a pro, on remote location for a shoot, (no matter if you are or not, though I am) the lab will do you good.
But, in the case of B&W, labs don't know what density you like. So, they'll run it for "the middle" (yup, THEY define middle) and hope that you fall into the 90% of people that don't understand B&W and just "think it is the coolest look".
I'll do this for hikes in all kinds of weather, the M&M mini's tubes will hold a roll of 120 perfectly and seal the tube against moisture. The ZIP lock adds a second layer of protection...
With that in mind, you could always shoot a C-41 B&W (yech, disgusting Shtuff), but it allows the film to run in a color process...