Make a few family sized meals like lasagna or cottage pie. I make them in a combination of pyrex dishes that can be frozen (but I have limited sizes and numbers of those) or larger pans that can be frozen (but again limited number). If you put a layer of greaseproof hanging out the top into it, you can remove the dish once frozen, wrap in foil over the greaseproof, and takes up less space and frees up the dish again. When thawing, take off the wrappings and put into the dish straight from the freezer, allow it to thaw, and then cook as normal.
The other option is to make "wet" sauces. So batches of things like stews, spaghetti bolognaise sauce, curries - whatever you want to serve. Freeze these in some larger batches (to suit your normal family size) and some in single portion sizes. So you can add in extra people to the pot easily (and it's easier to stack them and move them around the freezer). And single portions can be defrosted relatively quickly to add to the pot if you have an unexpected additional person at the table.
You could then do a curry feast night very easily - over the next few weeks, do a very large batch each week of a different curry for family dinner, and freeze a second family sized portion of each at least. For the Christmas period when entertaining, get out maybe a lamb, a chicken and a veggie curry, and reheat in the oven, and all you are cooking is rice really.
Or Chilli con carne and a chicken and mushrooms in creamy sauce dishes (so 1 spicy, 1 plainer) both served with rice and both could be from large batches of family dinners in the next few weeks.
I also do mac and cheese, with loads of bacon/ham, and veg (fried onions, fried garlic, fried mushrooms, uncooked pepper chunks, petit pois peas, fried or blanched courgette slices etc) as a family dinner. This is another "huge pot" meal, everyone eats loads, and when it's finished, leftovers get frozen to be recooked as a pasta bake with some grated cheese over the top. I do the same with leftover pasta dishes using a tomato sauce base as well - maybe meatballs and tomato sauce, or chopped up decent sausages like cumberlands.
The other thing I like to have in the freezer is already diced mixed medditeranean veggies for roasting - equal sized diced onions, garlic, pepper, mushrooms, courgette, tomatoes (cherry or regular fresh tomatoes) etc - marinaded in olive oil, salt and pepper, and some dried or fresh oregano/thyme/basil/rosemary (whatever Mediterranean herbs you have on hand), and maybe a slug of balsamic vinegar. They are great to throw in the oven alongside a roast joint or chicken joints (part boned breasts, or thighs/drumsticks etc) for a fast roast dinner (with a potato gratin or diced/partmentier type potatoes or mash).