Can’t hurt to do the spark plugs, but in reality NGK suggests a 70,000 mile life span on the original iridium plug type, despite Honda being much more conservative in their maintenance schedule. When you think about it, automobile spark plugs easily run 100,000 miles these days.
As for for the rest of it, I think you have it covered. Make sure your coolant and brake fluid are topped off. Hide a spare key somewhere on you or the bike. Some people have taken a spare clutch cable along on trips such as this, but frankly we’ve not heard of many cable failures thus far.