Hi Age - the campaign end date is set in the startpos file, and it can't be changed once the campaign has started.

As for your Viking thing, I can't actually read the date it's showing, but it looks like you're getting into the 'historical events' from the main MTW campaign - I don't think the Viking scenario likes that It's probably linked to the 'glorious achievements' timetable which will reference factions and provinces which don't exist in VI.

I think the only solution is to play faster