(I usually warm up my car for about 10 minutes before I leave for work. That defrosts the windows so I don't have to scrape plus makes the inside nice and toasty.)
There's an easier way to make scraping less of a chore, at least if you live in the US. RainX. Its a hydrophobic coating you apply just like spray-on car wax. Wash the windows, spray, rub to spread it evenly, let it dry, then spray lightly with water and buff. Turns 20 minutes of scraping into 5 minutes of scraping. Buy it near the spray-on car wax.
For my side mirrors, I pull a sub sandwich bag over the mirror and hold it on with a rubber band. Pull the bag, and the frost, off before I drive away.
I park in the garage at night, but snow and ice often starts during the day while I'm at work. And occasionally I have to work well into the evening, not leaving work until frost is forming.