If you were heading east it could have been the winds, we averaged only 5.75 from Oklahoma thru Kansas and partway thru Missouri and we had heavy cross and head winds all three of our travel days. I think it was the worst I have seen in 8 years with our HDT.
My wife and I are in our 70's. Our experience is with a 1996 25 ft class C Jayco with a bed over cab (my spot) and a rear queen bed for my wife. (We have no animals or kids.) It is pure joy to travel in and to live in. It would be a challenge to fulltime in it as a boondocker, lacking the large gray and black tanks as well as the freshwater tank. It does great in a 5 week trip.
You will have no problem with storage. It's built on a E-350 Ford chassis. Everything was trouble-free across our two maiden voyages.
We got into this for $10K.