Yes, I think you could cycle the RV17 upto Bodø but it will be very cold. You should also see if all ferries are running. I think there is one or two that might not be going yet. You will find all ferry links on the Trondheim – Bodø page. If one is not running look at the alternative options on the tap section on that page. You could head to the E6 and cycle up on that.