Worst weather you've ever serviced units in?

The worst weather I serviced a unit in was a Portland ice storm that left a solid inch of glaze on everything. My driver showed up for our weekly service visit when our only bathroom was gutted, and the standard unit was frozen to the driveway. He chipped the door open with a shovel, then used a pick to break up the ice inside the holding tank so the vacuum truck hose could pull waste. He told me operators add brine to tanks in winter to prevent freezing, but extreme cold still locks them up. For deep snow or mud, they extend hoses or use a portable pump if the truck can't get close. That day, he had to park on the street and run extra hose because our driveway was a skating rink. He said missed service calls in bad weather still get billed if the unit is inaccessible, so now I always shovel a path and salt around it before he comes.