A few things:
Signing a player permanently will require a two day medical, an incoming player would need to start their medical on Monday.
A loan with an option to buy wouldn't need a medical but wouldn't be attractive to clubs needing transfer fees.
When it comes to medicals, other clubs may be more gung-ho than Wolves so, in practical terms, selling is going to be easy than buying.
The perception that I have of Scott Sellars being quite a cautious person and will not want to make rushed decisions. I feel that he won't want to buy a player we haven't identified.
The clubs need not to make mistakes in this transfer window as Wolves at least need to get back to the top half of the PL to be more attractive to incoming players. (Yet caution on Wolves part, will make it far harder to get back chasing for European spots).