I don’t see how you can manage a temporary solution quickly in this time.
I would move in and especially keep an eye out for the beetles, document them, and then destroy them if noticeable. The pests spread via the beetles; the larvae don’t travel far. It might also be that only 2 floorboards are infested.
The manufacturer treatment is correct. The installer’s warehouse is likely the source of infestation. But you will never be able to prove that.
Since you need a replacement, only patience will help.
I would risk the furniture being infested, since they can also be treated individually and an infestation is not certain. The stress of not being able to move now is even greater.
Wishing you good luck, it really turned out badly.