Just another data point, but our company went back to work downtown this past Monday. Seems like around 90% of people are here every day.
Masks required when in hallways, public areas, or when within 6 feet of another human. Temperature readings when we come in, limited people on elevators, etc. My work area is mostly cubicles, so basically anytime you get up from your desk, you put on the mask. Other than that, people work from their cubicles.
Everything has gone fine so far, but it'll be curious to see what happens if one person gets it on the floor.
I also know of one other major downtown company thinking about coming back in around two weeks. Probably a staggered approach compared to ours.