6 week trip itinerary - but I have some specific questions

another thing to think about, you mentioned your inlaws are in their mid 70's. A little over a year ago, I took my parents on a trip in their MH to LA to visit relatives of my mom's. I re-discovered that they don't move fast. Never left anywhere at the time we planned. Also think about how long it will take to get going in the morning with 4 people and one bathroom. I used the bath-house wherever we stayed, to help move things along a bit quicker and still I really had to practice patience.