My personal opinion: That's a whole lot of driving for 5 days.

You will propably spend a whole two days driving up and down the coast on a relatively boring Croatian motorway. Plan for around 12 hours of travel from Montenegro to Vicenza.

If I were you I'd cut the Southern part of Croatia and concentrate on the Northern one. Not that Dubrovnik isn't a fantastic town, but for my very own personal taste that amount of driving doesn't really pay off.

Of course, if you like driving and long roadtrips then that's fine, I just want to shed some light on the amount of driving you are planning to do here.