Aye, did thought of that, but I wasn't planning on covering the entire Ring Road, that's why only planned for 5 days heading down south-east and back, but getting air ticket is proving to be a challenge (planning to use my Miles).
Plus, wife and myself wants to catch at least one Christmas market, so our transit is The Netherlands, gotta cater 2-4 days there. Iceland ain't that well known for the Christmas stuff, but I would like to see their free-for-all fireworks on New Year's Eve.
For catching of Northern Lights, it really comes down to luck. My sis friend just came back on the 14th Feb, managed to catch at least once. My cousin is there on honeymoon now (since 7th Feb, back this Sunday), so far no sighting. A lot depends on your present location and overhead cloud coverage.
PS: I've been monitoring
this site on a daily basis from my desk. Quite accurate readings as Iceland Met Service is more generic, plus they have sky cameras over the Scandinavian countries, so if there's aurora sighting over those areas, high chance of encounter over Iceland