solo is good too, chop chop everything, no need to negotiate with anyone, debate and argue
wah looks like you have an ambitious plan. you can still chiong Tromso lah, just move southward after your northernlight. for me, Norway is super expensive, if whole day dark dark and cold, after NL i would leave for warmer european cities liao.
i see that Tromso has flights to Chania, Crete island, Greece. maybe you can consider that for your south europe itin. or fly to oslo/copenhagen/helsinki, do a quick 2 days there then move on to south europe.