Hey mate, i have the same computer and used it for a recent trip.
I was lazy (and wanted to go off track at points), so had my main route (1500km or so) as one long file. I would turn it off every night and every morning turn it on, load my route and start recording again. The computer would take a min to realize i wasn't at the start of the route and would complain until it worked it out and navigation would continue as normal. Each day was saved as a different file in the history, but that was fine by me, i believe there are tools online that can stitch all the files into a single one once you get back home if that's what you prefer.
Hope this helps :)