Another way to treat everybody fine would be to offer to each account:
Explorer: 3/12 * 100 = 25xp
Silver: 3/12 x 180 = 45xp
Gold and Plat: 3/12 x 300 = 75xp

Depending on the final number of months of this crisis, those calculation can be adjusted.
It would help the members to maintain to their status or to move up to the higher status if they were on their way.
For plat or those who have already accumulated enough xp, they will still get an advantage and not the feeling to be punished without gift !

In my personal situation with october as a deadline, I already have 103xp out of 300:
- 36 are work-related in april-may-june depending on when we will be able to make it.
- 99 are supposed to be in July (if flying to the US is possible from Europe) --> if I can not make it, my status is lost whatever the scenario (even with the current or suggested "offers")
- 75 in october (if flying to canada is possible)