Northern Lights in Tromso Norway, returning flight to avoid a full day or travel

Planning a trip to see the northern lights in Tromso, Norway in December. Flying into Tromso from another major European city like Amsterdam or Paris allows for a pretty short transit - one layover with a total transit time of about four hours. The flight leaving Tromso to get to another major European city has me challenged. Going to Prague, Paris, or London directly after Tromso can cause the airfare consolidator websites to suggest 8-10 hr trips that involve multiple stops. I would prefer not to spend an entire day transiting to get to my next destination after Tromso.

Looking for ideas about itinerary to shorten transit time exiting Tromso. Perhaps visit another city not mentioned in my post? I know Copenhagen and Oslo are close to Tromso but would like to visit other cities besides those two.

Would especially like to hear from others who have done a similar trip.

Draft itinerary so far has:

Home USA

Paris

Tromso

Amsterdam

Prague

Home USA