Shaving in the field was zero fun during the camo face paint cold water days. Had my worst shaves right after standto. I found an MRE heater bag in a canteen cup of water made all the difference. Good luck to you brother.
This really is dependent on what your particular job and rank are. I'm not a DE shaver yet, but thinking back to my deployments so far I can't see when I would have been able to do it a lot. My deployed shaves have been cold water splashed on my face, no shave cream, and a mach3 razor.