We had a very well-stocked Brexit cabinet, but either used it up ourselves or gave it away to food banks when the COVID shortages kicked in. It's looking lighter now, but we regularly add back a can or two of tomatoes or beans, which we use up pretty quickly for meals. We usually keep a few different kinds of pasta at a time, because that's something we can always cook quickly and our kids will eat.
Freezer space is limited at ours: my fridge-freezer is annoyingly skinny. So, I do keep it full with frozen ingredients, but the actual amount I've got in there wouldn't fill half of a freezer unit on a typical American-sized side-by-side fridge. And there's definitely no capacity for a chest freezer at my house. TBH, my dad kept one growing up, but had to bin a ton of meat that he'd placed in there and forgot about for years. I would also forget chest freezer contents completely, or at best be so disorganised with meal planning that I'd never remember to defrost anything in time.
I did buy extra paracetamol and ibuprofen in the lead-up to Brexit. The adult tablets were slowly chipped away at as required and worth having to hand, but it wasn't worth having more than one Calpol. I'm going to have to bin a nearly-full bottle of generic age-6 paracetamol because it wasn't used up before the expiry date. :(
I've seen news about Christmas being "ruined" potentially because of supply issues. I'm trying to take a more zen outlook on that now; if I can't get what I expected to for a Christmas meal, I will improvise. Vegetarian Christmas if I can't get meat, or I might get creative about what other countries serve at the holidays and see if I can improvise. If I had to go without booze at the holidays, I'd be a bit boo-urns about that, but I also know I'd be fine.
As far as gifts go, we've had fortunate years and leaner years as a family already. As long as the kids can see we're in tune with their interests and likes, we can usually find a way to put a smile on their faces with presents, regardless of what we can acquire for them in a given year. I try to spread out the cost of Christmas by picking up things for their stockings here and there in September or October, but the danger there is Ive often forgotten what I purchased until Christmas Eve.... so the strategy has had limited benefits for us.
We do limit the lengths of our kids' Santa lists and remind them every year that Santa can't always bring everything they ask for. Santa doesn't bring expensive things like iPads to our house either. I definitely started that with our family because of the social media meme, but the concept has also let DH and me off the hook when we couldn't manage a super expensive gift in a given year (and when we could, we took the credit).
Clothes for my youngest are just hand me downs from the older two. I have tried buying ahead in sales, but it's a waste of money: by the time the older DDs grow into the thing I've set aside, they usually hate it and have a completely different style.