RUMBLETiGER
Adventurer
You could use the Shrink Item spell. If your workshop is a small, free standing structure, like a tool shed, a reasonably low level wizard could shrink it.
A 10th level wizard could shrink a 20 cubic foot "workshop" shed to a patch of cloth about 16 inches wide, fold it up and put it in his pocket. It would stay that way for 10 days, or until he tosses it on the ground or gives a command word. Since Shrink Item is a 3rd level wizard spell it would be pretty easy to re-prepare the spell every couple weeks, or just make it permanent with the Permanency spell. You might need to ok it with your DM that all the shed's contents shrink with it, but even if not you can carry them around in a wagon, set up shop as part of normal daily camping duties, and pack up after last watch. Plus it gives the whole group a safer place to sleep that can be well secured with magic and is very safe from the elements and inclement weather.
Just watch out for antimagic fields
Scott
Now This idea has Merit!