Heathrow SC was open last week. They replaced my MS PTC heater (it blew up with a loud bang), booked via the app with a waiting time of about three weeks. The service desk is marked off with red tape so you can only stand just inside the sliding door and keep distance from the staff. At pickup, the service guy went to hand the key to me directly but I stood back and had him place it on the car roof, where I picked it up with gloves that I wore for the drive home. While I was getting ready to leave, two MS Tesla mobile service cars pulled in, so I assume they are functioning.
In a phone call the day before service, I was warned that this one-day repair could take longer as they were working with fewer staff, but in the event it was ready end of the same day.