I do think its time to get something in place to be fair, then you know your ready, ive just got a tank with immersion heater in, a couple of aquarium heaters for my ibc, the RO is tucked up nicely inside now, never leaving them outside again (after smashing 3).
Ive also built up a trolley and have barrels that ill keep inside, not that i want to really use that but if the van frozen thats what ill need to use. How ever im hoping the immersion heater in the tank will act as some sort of radiator in van like ive read on here and keep van nice and warm...i aint getting stuck this year. Last 2 winters killed me and almost made me sack the job off!