Insurance has nothing to do with it, it has to be SORN'd even on your drive private land or anywhere!
No vehicle requires insurance if not used on the public highway and if it's on the highway all the rest applies MOT etc.
Trust me i know 1st hand, if it's not SORN they WILL clamp it, with a 48hours notice then on the dot they will take your vehicle, impound it, then you have 7days to get it back after various charges are payed for, "low value" vehicles will be crushed, more valuable will be declared recovered and sent to auction.
I had the 1st one done to me.
Also a side note, if anyone is restoring a car, or a car you love is off the road, then get an insurance quote with the average mileage declared as zero,
my last insurance for a vehicle off the road was £150 TPFT, its classed as very low risk so insurance is minimal but deffo worth doing.