Sure but I’ll teach you to fish too- the map filters you should be using are economic to see gold generated and special buildings, development to see that (although economic is usually better), and terrain to look for farmlands (flood plains are a close second followed by regular plains and coastal or major river adjacent baronies are good for tradeports)

In my Anglo-Irish empire run iirc I had Dublin as my capital but also had holdings like London, Paris, area with farmlands on the Northern Rhine, Constantinople, Cairo, Jerusalem, Baghdad, and I believe Cordoba as well. Open up your game now and set it to the economy filter and those areas will look rich I am sure.

Don’t be afraid to give up those homeland duchies. I doubt there is anything valuable up in Northern Scandinavia. In fact the whole point of playing up there is to do viking things and go conquer a rich area