I have taken a few long trips over the last few years...Central North Carolina to Cabbot Trail, Nova Scotia. San Antonio to northern Maine/New Brunswick. Planning on doing San Antonio to Anchorage, Alaska over a 16 day period (limited time due to how I can schedule vacation) in late July-early August. Having taken some longer trips, I've gotten the packing down to small, requisite items, and plenty of layerable snivel gear. Plan to take the fastest route to Anchorage, have dinner with a friend, then take off again, but drop down and pick up the pacific coast highway in Oregon and take it all the way down to I-10 then zip back across ASAP. Due to the wide temp variability, was planning to load up on layerable gear, no camping equipment and stay in hotel/motels only. Looks like about 9000-9200 total miles. Will be on a 2013 1200RT. Will be at about 26,000 miles on the bike, about 2k after the 24 service, Amsoil, and on a set of Michelin Pilot Road 4 GTs that will have about 10k miles on them. At 8k now on those tires and they're wearing great.
Any advice for a trip this length over that time period, advice about area conditions, other advisable bike prep, or areas/pitfalls that could result in an epic fail?