I’ve used hot water lots of times, BUT never use BOILING water, only hot water tap water.
Is it possible that doing this would stretch out the springs and cause the wipers to have less prssure againstd the windshield?
No. The springs are stretched about the same amount on the window as fully up.
You can buy these “frost shields” for different size cars at most auto supply stores. It tucks in the 2 front door seals, and save a lot of hassel in the morning when the car is left outside. I’ve used one for years. You still have to scrape of the rest of the windwos, of course.