Taking elderly in-laws (86 & 88 ) on 500 mile trip.

My father was in his mid 80s when he went with us in the MH and my mother was over 90 when she was still going with us. We usually travel until we get a little tired and then find a spot for the night. We don't do well with schedules of so many miles. One time it took us 5 days from NE Detroit to Atlanta, GA. Another time we made it in one day.