appreciate the advice!
I assume that "unimproved road" means the same as unpaved? I think Canada (at least in Nova Scotia) has less google streetview coverage, so mostly only the major roads are covered. Didn't realize the route I was looking at might be unpaved, so you've saved me an unpleasant surprise! S. Tropical Trail looked pretty, but being buzzed and tailgated doesn't sound so fun.
With that route down, and as the Beachline Expressway (528) is obviously unsuitable, the only other choice seems to be Irlo Bronson / Space Coast Hwy (192). I can guess it's a busy road, but streetview suggests there's a bikable lane, and I am used to similar roads where cars are driving 60mph roughly. Not my first choice, but I can't find any other way over that wouldn't exceed 70 miles to Indian Harbour (my limit for the first luggage-carrying ride of the season!) Any advice on this one?