Mostly likely you want to make cleaning/improvements to the house because
the former owner can not do a too good job during this time, like deep
cleaning of the carpet which I am sure you want to do it to feel comfortable
. With your own stuff, some jobs will be much more difficult. For things
like paining, it is much better to do it without furniture and people in the
house. If you think you can manage with that, sure you should move in as
soon as possible to save money.