Your suggestion would require a complete change to when energy for a job is deducted.
not really.
the energy system would only have to allow for a negative number and then only IF sleep was the current activity.
in other words
if your energy was currently at 7 and you slept in a janitors closet for 8 hours .. you total useable energy at the end of the 8 hours would be
64 + 7
as long as your queued activities after sleep did not make your energy fall lower than -64 you could add any activities to the assignment queue
as long as the activities applied from the negative number were not greater than (zero+your current energy) , you could queue the activity.
it is still a logic change, but it could be implemented without reworking the entire energy system as it relates to the rest of the game.