The guys on Simcoe had Quanset hut type shacks that were about 10' wide x 20' long..heated etc. with bunks..but they moved them with 10 passenger snow cats!
I've often thought that if you were gonna build a shack you could use insulated aluminum garage door panels for the exterior walls and possibly the roof...they're light and have good structural qualities...
Good luck!
RGFIXIT