My class 2 is due to expire at the beginning of April. Last I heard from my AME (Monday of this week) they're still open for business.
I have a medical booked in the very near future but given that none of us are flying at the moment, my thoughts are let it expire and sort out the resulting bureaucracy later on in the year when (hopefully) we are all allowed to move around again. My only slight concern with this approach is whether or not it would then be treated as an initial issue and additional jumping through hoops that can entail. I'd like to think that the CAA will apply some common sense here and handle these as delayed renewals, but who knows!