I have nothing but good experiences with dealerships while "on the road". They get it and usually can get you taken care of in an hour. Last summer we were at Copper Canyon in Butte, Montana, they changed all three fluids for me in about 75 minutes, plus a new set of plugs and checked by rear belt tension. It was the end of the day and we already checked into our hotel. Got there at 4, out the door headed for dinner by 5:30. To me this is typical of what I find on the road.

As far as oil, I agree the synthetic should hold up fine. Quick story, rode from NYC to Cleveland on my Sportster, 2 up, almost twenty years ago running Castrol 20w50. When we got to Cleveland (via Niagara) I went to check my oil the next morning, it had broken down so bad I couldn't even get a reading on the dipstick. I just slid right off like brown water. Found an indy nearby, bought 4 quarts of something that wasn't Castrol and we continued our trip. Whatever I put in made it back to NYC without a full breakdown.

That was last time I used Castrol in anything.

 

Sucks to hear that. I just did an oil change using that oil. Maybe in 2 decades something has changed. Maybe not. I'm going to give it a good look today.

I usually run 20/50 V-Twin Mobil 1. I thought the same as most here - I could start a trip with a fresh oil change and do it again when I get home. On our last trip, we put on only 4000 miles - about 1000 short of the recommended interval. The engine was making "bad" noises in the upper end, so I brought it to the dealer. They heard the noise too, so I left it to be evaluated. They called me later in the day and told me tat the oil was filthy and worn out. When I picked up the bike I explained to the guy that the oil was 3 weeks old and had 4000 miles on it. He looked at me like I was a child molester and said I was wasting my money on synthetic and that regardless of what the manual says, I should change the oil every 2500-3000 miles - even when traveling. I thought he was going to wheel the bike away and put it in a bike shelter for abused motorcycles the way he acted.

That said, with the new oil change the noise went away and I haven't heard it since. I guess I would be cautious about running any oil for that long in an air cooled bike after my last experience. YMMV

 

I would run the 8k miles starting on a fresh oil change, then get a UOA when you get back. You'll find out that the oil could have gone 10k.