My ideal is working remotely from home, but coming into the office once a quarter for the whole week, and spending that time doing interpersonal things. I come away from that week feeling very refreshed and enabled to dive into work again with solid focus.

I'll rarely make any progress on my "sprint" tasks during the in-office week, but I organize fun social events after-hours for all the other remotes that fly in at the same time (and any locals that want to spend after-hours together). Last time I did a screening of Princess Mononoke in the main office gathering area, and then we went out for drinks & dinner 2-3 times that week. One evening we all went out to play ping-pong.