Just book a week in Spain with one of the various mountain bike package companies over there. Yesterday I’ve come back from a week with Switchbacks, Malaga. 6 days riding, a lot of descending (20,000m elevation of descending), no mud to be seen anywhere. Not had to clean the bike or lube the chain all week. Plus the riding over there is even better than what you get in England when its dry. Spain is definitely the solution to the mud problem of the UK Winter.
For normal Winter rides in the UK I tend to ride the least muddy routes (even if it means driving further), put three mud guards on, wear full length pants to protect my legs from the mud, wear waterproof hiking boots with flat pedals, use my secondary bike rather than my best bike, ride less often (once every week or two) and if I need to get out more I’ll consider going on a Walk instead of a Ride sometimes.