A Very Space Marine Gift - Advice Needed (1.25)

So, playing as Great Britain. Playing tall and colonial. Allied with a blobbed Brandenburg. They call me into war. I join to give France hell since they are allied to the main target. Brandenburg offers land too. Things going well. Too well. We kick France around. Brandenburg grants me Nemours AND Paris.

Here's a link with the dilemma.

Any advice on what to do with these provinces since I'm unable to core? Any potential work arounds? The other problem is that everyone in the general neighborhood is ultra pissed off with me for being granted Paris and Nemours—so I also fear a coalition.

My guess is that I'll have to take a prestige hit but I don't want to just jump to that conclusion. I'm not super experienced in this kind of situation.

EDIT: I apologize for my redundant title. I don't post often and didn't realize I could categorize.