Good point about room sizes. You might want to tip more for a larger room. I stay in a studio & wash my own dishes, make my own bed, rinse the tub & sinks, even sweep any sand that sneaks in. Housekeeping staff basically empties the trash, changes towels, washes the floor, changes sheets.

Since I know the staff well where I stay, I know that sometimes the big tip at the end can cause friction because of exactly what I described. Not good to put people in that situation, certainly not fair to the person who has done 95% of the work to get 0% of the tip you left for them.