Milan*
Both teams are planning on leaving San Siro.
Milan have a deal with a company that owns the land on which the stadium is to be built, in the comune of San Donato Milanese.
Nothing concrete yet, although management has repeatedly announced they want to play the first game there in 2028.
Inter have spotted a couple of locations in the comuni of Rozzano and I can’t remember where else, but just like Milan, nothing concrete yet.
Almost certainly not in January, in the middle of the league and Europe.
If they do end up selling him in the summer, I see very few teams that are able to offer that much.