Renew your C1 licence for motorhome vehicles over 3.5 tonne at 70. Full D4 medical only £55 nationwide helping you retain your entitlements.
d4drivers.uk
Check out these people Ron/Penny
I could be mistaken but I believe their medicals are good for two to three months.
In other words, you could apply for your C1 before you leave in December/January. They only charge £55 for the medical inc eyesight.
Worth just asking their advice. I’ve used them twice now, and they are spot on. You can walk into any Post Office and ask for a C1 pack and they give you an envelope containing everything needed.