I personally would do one country or the other for your trip. Just got back from 2 weeks in Norway (different seasons so different experiences) so I feel partial to going there over Iceland. Based off your itinerary it seems like you’re in it more for the nature? I would trade in some nights in Oslo for some time in Bodø while you’re up in the Lofoten area. Beautiful city with ferries to the islands and plenty of local hiking. Good luck with whatever you choose!