I don’t see why you can’t do it if you are clever about what you serve.
Choose things that do not need to be refrigerated or kept warm in the main.
A variety of breads - large loaves of rye, seeded, sourdough, whole meal, rolls, slices, etc. Also add seeded crackers, cheese crackers, water biscuits, cream crackers and pumpernickel. Scones - fruit and/or cheese - easy, cheap and fast to make. Slabs of butter for spreading, wheels of cheese as above, a big tub of cream cheese and an array of savoury jams and chutneys. A fruit board with melons, berries, grapes and pineapple, colourful, big fruits you can slice into sections or wedges easily. Tubs of olives, sundried tomatoes, artichokes, crisps, nuts, pestos and dips - Hummous, guacamole whizzed up in batches. Big green salads, crudites, array of premade dressings, big stand pies from the butcher. You could add meat platters but you wouldn’t need to. Just fridge what’s necessary. Choosing fresh food with few meats and a lot of dried, sealed or preserved items will help.
You can do lots in advance tray bake style. A brownie bake, a big rocky road, a parkin or a marmalade gingerbread, Do a big tray of sponge and top it with jam and coconut, do another and top it with lemon icing and zest, do another and top with orange and pistachio, whatever you like for little effort, our standard tray bakes feed 20 and can last days at room temp, covered. The marmalade gingerbread tastes better when it’s a week old.