I would factor in a minimum of 1 week to ship there, 1 week back (maybe less if you did an overnight). Then maybe add in a few days for processing, pray that they can fix/ replace your board within about a week (my old lenovo was sitting at the lenovo depot for about a month after before they finally took action. only after angry phone calls). Add in another day to get it ready for the return trip.
I'm only doing a very rough estimate, but in my experience unless you are lucky, computer repairs take 2-3 weeks minimum. Maybe a bit less since they can just send you a new board if they want, but even still the shipping time can take a while