I work from home a lot anyway so these last 8 months have been fine. Post pandemic, I'll be less likely to jump in the car during inclement weather to get to a meeting. I'll just reschedule to Zoom or Teams.
Same thing for the regular bi-weekly meetings I have in my calendar. I'll probably switch to 50/50 in-person and Zoom/Teams. It's important to meet face-to-face monthly, but the Zoom/Teams set up saves so much wasted time driving to and from the meeting location. Everyone I work with recognizes this efficiency.
Beyond that, a number of firms I deal with have put off or cancelled acquiring more office space. They are going with flex desks and days so people rotate between working at home a couple of days and coming into the office. Most people won't have assigned desks, there will be work stations. I think that's a fine way to be more efficient with the current office space. I mean, if you can't trust your staff working from home a couple of days a week, why did you hire them in the first place?