Welcome to FT, tomeck!

You may want to check the SAS forum here at FT (use the search function once you get there) as similar things have been discussed before.

Personally I don't think it should be much of a problem as long as you stick to one alliance (which you do in this case) and also have a decent transfer time in LHR/CDG (both to convince the check-in agent it's doable and in case they refuse through check and you need to recheck-in).

I would guess the chance of success is higher if you fly out of GOT as they may be more used to these 'unusual matters' than smaller airports like JKG.
Also if you have status with for example SAS (EBS or EBG) it may certainly help a bit.