For years now, I have WFH two days a week, and gone into the office three days a week. In the current situation, I'm WFH full time now, but its really no difference for me. I generally work the same amount of hours that I do when I'm in the office. While WFH, I will occasionally log on a little early or stay on a little late. But I also will take a break to throw in laundry or let the dog out. When I'm in the office, I work more set hours, but will take breaks to walk to the cafeteria, restroom, chat with co-workers, etc. So the amount of time I actually spend working probably balances out.
WFH definitely has its benefits, but I do feel more productive when I get ready and go into the office, so I'd probably like to return to my normal schedule of 3 days a week in the office when this is over. I think that's a good mix. I also find that our VPN is slow, so its easier to save and work on larger files while on the office's network.