According to Dexter axles their products are tested to -40c being a standard in the industry. In Alaska from personal experience in Fairbanks and Kodiak fiberglass plastic holds up to -50F, past this point the plastic gets somewhat brittle and on impact goes to a granulated powder like dust (like sugar) leaving behind the matted fibers underlying it, I have no idea about modern plastics today only the old formulations from snow machine accidents regarding cowlings in the early 70s, they were prone to this type of damage...By -50F unless you are using synthetic, your wheels on both tug and tow would be locked solid needing to be put into a garage to thaw overnight to repack the grease in them with synthetic.
The vehicle would start to have issues aspirating fuel in the cold much past -65F on a stone cold start unless the engine were pre-heated...A propane
block heater is what I used to use in the boonies. I have shattered frame welds at past -7O on shock mounts...Tires are frozen flat on the bottom by then, the shocks are a has been issue being now solid rock, moving to soon sets off an awful vibration that seals the deal on cold metal...As my Yucon cousins know warming the beast up 45 minuiets turns it into a vehical again, the foam in the seats might as well be ice slabs. Interior vehical heaters prevent splitting plastics in the seat when sat on, these heaters heat up interiors enough to keep them pliable. Batteries fail without heat in about the same range plus or minus 10 degrees depending on state of charge.
Good news! 0 degrees F is no where near that!
Driving wisely with basic saftey measures you will do you just fine!
After Alaska (64-77) my home in Arizona since 1977 is just what I want.
You are a hardier breed than me.
Happy camping, Safe journeys always.