Yep, have lived all over - Devon, South Downs, now Lincolnshire, but always in out of the way cottages in the sticks. Never had mains drainage, and often not mains water.
Trouble is when power goes off, these sorts of properties are just not a priority to get fixed, so freezers can be problematic. I have a gennie back up, but that's short term.
Water is easy for me, stick a bucket down the well. The frost line (depth of frost) doesn't go more than a foot sub surface here, so the well doesn't freeze (checked it at -12 and it was fine - doesn't get much colder). If I didn't have that, I'd use water butts gathering rainwater for toilet flushing etc. and keep a few plastic camper type water carriers (like a Jerry can with a tap) for drinking. Keep them clean and the water lasts forever, but I'd rotate every six to twelve months jsut to be safe.
The best way to keep air out is an oygen impermeable bag (often known as mylar). These bags can be sealed with an iron and an oxygen absorbing sachet put in to absorb any oxygen in the bag already. The bag will shrink like those foil pouches of coffee. Something like rice stored that way is good for 25 years and can be left in the back of a cupboard. I put them in a plastic tub with a lid. That keeps any mice etc. from chewing into the bag.
Not really necessary for a big snowfall though. I reckon if you can manage for a few weeks, you are good to go. A 4kg bag of rice, some potatoes, a couple of bags of kidney beans, some chilli powder, some corned beef and a tin of bacon grill for brekky. Thats chilli, corned beef hash and a bacon brekkie - and I'm happy to eat that any time so it doesn't spoil
Having a backup light source, heat source and some water is always sensible to get over a storm problem etc.
Red