We winter in Nice and are considering a short trip from Nice to Corsica in March. We would fly in and rent a car. Trying to decide which airport to fly into and then what city/town to stay in to be able to access much of the island via car. Would probably stay about a week.
Corsica is a rugged island so be prepared for tight, winding mountain driving -- nothing like the flatlands around London, Ont. (all the way to Windsor where I live.)
I'll second that - a lot of the driving is pretty hairy, and also takes far longer than one would expect. Took ferry to Bastia (mine was from Livorno, but most folks sailed from Nice), and drove an hour and a half to get to accommodations 11 miles away. Corsica is gorgeous - just be prepared.