mate... d'hara has been sitting around for a month doing squat. it doesn't take that long to get to the lighthouse really.
it would take you 52 hours to cover the total distance of 643 miles, assuming no travel delays.
That's for the lighthouse only. Then you got another sea route, 'cause the Lighthouse rarely has anything in it. Then the fun roads in rogue regions... Sallowtown to Desert of Silouhettes is incredibly long, if I remember correctly.