In the northern climates especially, the recommendation is to always relieve the pressure from the lines and leave at least a couple of valves open partially or all the way. Though antifreeze should prevent a solid freeze, it will start to get slushy when below freezing and will expand as that progresses with colder temperatures. Add into that equation that you never know for sure you have removed all of the water from your lines by blowing them out.
Even in cars and trucks, there is room for expansion and contraction of coolant.
2020 Eagle HT 30.5 CKTS Modern Farmhouse (16" wheels, spring shackles set on lower hole of frame, SumoSprings TSS-107-40, standard kingpin, B&W Companion slider, TST-507 TPMS, Progressive Industries hardwired 50A EMS HW-50C)
2019 F250 SRW SuperCab 4X4 SB 6.2 (10,000# GVW) 3.73 Axle 18" wheels