I've done it two ways. I've changed the oil a day or two before a long trip at my trusted, local garage.
I've also had the oil changed at other places along the way on a long road trip.
Once at a fast lube joint on the road and a couple times at a Chevy dealer on the road.
All three times I either picked up my oil choice (Quaker State) ...or had QS along with me for the change.
At the fast lube joint the guy tried to flim flam me saying I needed a new air filter....at one of the dealers I didn't have confidence in the ability of the oil change guy.
I felt better with changing oil at my usual place.....just before the trip.