Stream do an insulated truck mounted tank all the working parts inc DI vessels are inside an insulated cabinet, I have always filled the cavity inside the cabinet with insulated tank blanket to prevent freezing.
Poles and hose reels go in the garage over night then I just load the van up before going to work in the morning, the half inch hose feeding to the external ports can be disconnected and put inside the van wrapped in insulation, using pipe insulation on your half inch hose also helps.
As for stopping your pole hose and micro bore freezing whilst your working on the coldest days....well good luck..I guess hot water can only totally solve this ..
