Do upgraded rooms require more power than non-upgraded rooms?
Can I get away with building less power infrastructure if I go with a smaller number of heavily-upgraded rooms vs a larger number of non-upgraded rooms?
Solution 1:
Upgraded rooms require more power. (Source)
However, you will indirectly use less power by using a smaller number of heavily-upgraded rooms, as you will need fewer dwellers to man them (requiring less food/water -> requiring fewer food/water rooms -> using less power).