Charged all 3 cars again.
Given the amount of time they spend plugged in, you may as well go all electric... 
Probably being over cautious, but work on the principle that most cars will hit the battery hard after 4-6 weeks of non use, and that long term partial discharges permanently damage the battery, so try to charge every unused car every 2 weeks or so (maybe 3 weeks on the Battlebus, as I normally have to look for it).
Both of us are WFH, so during the currently period, the Zaf is allowed on the drive, and the Pussy gets no use either, so may as well charge them when its dry.
TBE is only doing short Tesco runs currently, so also keeping that topped up, although it does do the occasional mercy run, and that will be going back to 1k oil changes, until this sniffle panic blows over.