Thanx for all the replies.
I think experience will be "my" best teacher. Weight is an issue along with cost. I to have to stop every two or three hours for the dogs and stretch my legs. I had a blood clot a while back from sitting way too long. I like the idea of having enough reserve to pick my fuel stops, but there has to be a trade off. A spare 5 gal can for now
Thanx again
Dean