I've broke a windshield wiper off my truck. Finally got the door open by pouring coffee on the handle , holding it open while I pryed on the door with a hay hook. Poured coffee again on the keypad to my front gate opener. Had the foresight to know I was gonna have trouble with gate latches and locks so I took a propane torch, that worked ok. I've left all gates just wired for now. I've tried all the boots I own. Best I've come up with is a pair of my son's rubber boots, he's a couple sizes bigger with a half dozen socks on.
You northerner's help us out... we're fighting a unfamiliar enemy down here.
Pouring coffee or hot water on things that are frozen will help you get them open, but you can expect it to get worse as you've just added more water so it will ice up thicker next time. You would've been better off with a hair dryer or alcohol, medicinal cleaning type as it will evaporate.
As far as dressing goes, loose layers is much better than bundling up tight. The layer next to your skin is good to be tight, IE t-shirt or long johns tight to skin, then a loose pair of jeans and loose long sleeve shirt next. Then over the top a loose fitting coat and coveralls if you have them. Basically, try to keep air gaps that your body is heating and keeping heated close to your skin. As far as your feet, if you put a 2nd pair of sock on, you want them loose and it's better if your socks are not cotton, cotton absorbs and holds water, once the water, sweaty sock, is cold you're done...you'll never get them warm. You could take a bread bag and put it outside your socks to try to make that "warm air pocket" I described with clothing. The problem with the plastic bag is it won't allow any moisture out, and the worst thing is having wet feet...once they get cold it takes forever to get them warm. Wear a hat and a scarf, heat rises and this will help keep the heat in...
If you have hand warmers, carry 1 or 2 in your pockets and use them on your hands as needed. Blowing on your hands will make them feel warm for a couple seconds, but there is too much water vapor in your breath and they'll get colder faster every time you do it.
Unfortunately good insulated boots are expensive and I doubt you'd want to spend $100 for something that you might only use for the rest of this week. Those old 5 buckle rubber boots that you wear over your shoes can actually be very warm, but they cost money too however you'd probably get more use out of them as they're great when it's muddy or wet.