I had a block heater, an oil pan heater, and an interior heater in all my vehicles. Synthetic oil certainly helps a lot too. What I was thinking of was the tires getting frozen solid. Two-wheel drive vehicles would often be hopelessly stuck. The 4X4s would always move; but the tires, and hydraulic shocks would remain frozen solid. You had to move very slowly for a couple of miles, until things started to warm up a bit.
I have had manual transmissions with conventional gear lube in them that took a good fifteen minutes of feathering the clutch in and out to get limber enough to engage the clutch without killing the engine. The first couple of miles are always a shakedown in that weather, and every vehicle I have driven in such cold makes an entirely new set of noises they don’t make when it is warmer...