Mbappè can't leave in January if PSG doesn't want to sell him, but if Madrid is able to buy Mbappè at the agreed price I think PSG will let him go rather than PSG having to lose Mbappè without getting any profit because Mbappè is PSG biggest investment at the moment so let it be this player being free is a painful thing, if in the end Mbappè leaves PSG, I don't know what will happen to the team because so far Mbappè has been a key player for PSG in achieving success, whereas currently PSG doesn't seem to have any rumors relating to the striker Mbappè replacement.
Usually as we approach for the transfer window we have many rumours and other related things in news which create good heat, and we also have good masala from the media so now same happening while we are jumping for the transfer window many reports are coming about Mbappé even nothing is official but still if we have Mbappé out of the PSG then surely management will bring suitable replacement quickly because they also understand impact of this transfer on team.
But, in case he leaves then surely something happen, but they are capable of having recover from this and bring positive changes as well with most chances we will have Victor Osimhen and Vlahović as his replacement at the PSG few weeks back we have talked about this which clearly indicate Mbappé and Luis Enrique are set for working together but now we to wait about this all how this all will be ended.
To be honest I don't think Mbappe will leave this winter from PSG. First of all, PSG may not be interested in selling him and convincing him to get another contract. But I think Real Madrid really tries hard this winter, they can get him. After all, if Mbappe leaves next summer it will be a huge loss for Mbappe. But Mbappe can be sold at a good price right now. But if he leaves in Summer, there will be no price to pay to PSG. Real Madrid will have to pay Mbappe for the signing bonus I suppose.
I heard rumors that Real Madrid won't be signing any new players this winter. If that is true I don't see Mbappe leave this winter. After all, not any clubs can afford him. Liverpool are interested in him but I don't see him joining Liverpool. And the other clubs that can afford got no place for them in their team.