I'm in the process of writing my post, slowed down by a real life (paid! and therefore urgent) work project that I should be able to finish today. I plan to take the -Ship directly to the Havens (
You shall not pass GO, you shall not collect 30 silver pennies!). The only possibilities for a diversion between the Shire/Mire and the Havens that occur to me (*consults map) are the White Downs/Far Downs and the White Towers. (See 'The Grey Havens', RotK) Unless, (highly improbable, of course, but since when has that ever stopped us?!) we detour by way of Lake Evendim/Annúminas, but I've no idea for any adventure there. Should any of you have a cunning plan, please let me know posthaste; otherwise, I'll just get us there in record time.
edit: According to my handy-dandy Foster's Guide, "The Towers remained standing into the Fourth Age." Now, either we accept that (canon instead of cannons, for a change?!
) and avoid them, as our presence would most certainly be destructive in nature - or... we take that as a challenge!