If your speaking of "we" meaning "me"(as in a single person), then sure you can get by with a good deal less than 1000 sq. feet. Trying to squeeze a family into a "house" of 300 sq ft or whatever is not likely to go well. For a few it might, but they'll be the exception. It isn't just a matter of downsizing possessions, it's been well documented that cramped living breeds issues with physical and mental health. YMMV

"Cooking and bathing under the same roof are luxuries..."
Maybe in a third-world country, here there considered 'standard equipment'. How we do take them for granted, I will admit.