I can only speak from the experience of having lost my power for weeks at a time before. Items with a big current draw are gonna be the things that heat or cool: heating coils draw a lot of juice: electric heaters, electric water heater, electric dryer. Big motors also pull a lot of juice: Air conditioners come to mind especially.
If you can get along without those things, most likely a 8k generator will do you. Simply having lights that come on at the flip of a switch is huge. If you're on a well, you might check to se how much current your well pump requires. Also refrigerator and freezer, probably not a big deal over the short term but for multi day outages it's sure nice not to have to worry. Of course, at this time of year you might be able to just set stuff outside in a cooler to keep cold.
For reference, I have a 4.5 k generator that will easily do what I need, but I have gravity water and a gas water heater and stove. My elctric dryer does not work at all on the generator, nor my little floor heaters (they probably technically "would" work, but they pull down all the other stuff). Refrigerator and chest freezer and washing machine all work fine, as do all lights and electronics (I've been trusting my power strips to protect those things, none of which are real high end items).
My generator is over fifteen years old with a Briggs and Stratton engine, a real howler. I park it about a hundred feet from the house and feed through a chunk of 10-2 romex (underground feed) to power up both bus bars in my panel (through my dryer outelt).
For other reasons I had to have a "hard" disconnect switch plumbed into my elctric hook up from the pole. Once I'm certain I won't backfeed into the circuit and kill a lineman, I live a pretty normal life on about 5 gallons of gas a day.