You're fortunate to have access to a work shower (even though I'd want to bleach the heck out of thing thing before using it). In my last place, the one bathroom went out leaving me with no toilet or shower access. This is NOT a good thing and I was thoroughly squicked out. It didn't help that it was August, and hot, hot, hot.
Fortunately, there was a small family-run food market (produce and other goods) around the corner that had two really nice bathrooms (women and men) it let customers use. The shower was harder, but what I did was to shower twice a day in the garage with the door open just enough to admit light but not enough so anyone could see under it past my knees. (Not that anyone could see without peeking.) I turned on the garden hose, had soap, shampoo/conditioner, towels, etc. with me. The water was *cold* at first but after five minutes or so felt warm, almost too warm by the end of it. I thoroughly scrubbed and felt really clean each day. Not something I would care to repeat again, but entirely do-able. And much better than being without a shower.