We were already knowing Real Madrid's high interest in Erling Haaland for a long time. But I assume that they won't make an offer for Haaland in January already. Dortmund wouldn't be willing to sell him right away. And even if he really has that release clause, Haaland wouldn't like to leave the team before the end of the season I guess. But this summer, it is obvious that some club will manage to sign him.
We don't even know whether the deal is already done. Although Haaland isn't allowed to negotiate with other clubs right now, we all know how these things work in the end. Rail visited several club managers already and Haaland's father was also seen with other club managers. I think there is zero chance for Haaland to stay in Dortmund given that they essentially have no chance to win the Bundesliga, are out of the CL and also out of the DFB Cup.