Highway 1 up the coast

As stated above it's doable but can be very slow especially on week ends in the summer. Lots of touristas.

Funny. I have told my wife one day I want to drive this route to Key West and wondered if it would be worth saying we drove 'Route 1' the entire way.

No problem at all, just did it in reverse.

We live in greater Portland and never take Route One between Portland and New Hampshire, unless we have some specific destinations along the way. It's not a bad road, but it's mostly commercial, not at all scenic and takes a long time because you go through many towns and several cities. The Maine Turnpike (I-95)is a much better alternative--connects directly to 295 just south of Portland. It's worth the tolls.

Lot of traffic lights on route 1 but doable.

Very doable