One person and a cat here, in about 275 sq. ft. This number is from my own measuring I just did with a measuring tape, so give or take a few.
That seems really small when it's put in a number like that! But really it feels luxuriously spacious. It's a beautiful home, and we're totally happy here. It doesn't hurt that we're coming from an even smaller apartment without a sunroom (I did calculate the sunroom space!), which housed another person for three months last year.
EDIT: Added pictures!
Not pictured: bathroom and front entry, which has a closet for shoes and tons of extra storage. Sunroom also not really pictured--it has suitcases, my cat's carrier, a big foam mattress pad, an electric fan, and my cat's bed (and cat, right now). Having the sunroom really makes my space seem bigger because those bulky items I'm not using at the moment are hidden away. From my view, anyway--I'm sure neighbors can see them ;-)