In our case, we had many different errands and stops along the way. Let's see, in order: Stop to get the mail from the Sunnyvale PO Box; coffee stop in Livermore; fuel at Lodi Junction; two fruitless attempt to find a place in Sacramento for which we were looking (not vital, but target of opportunity); Fry's Sacramento to pick up things, and get take-out lunch from fast food next door; Colfax restroom stop (and chance to get the California redemption value from our cans and bottles from this trip); Sparks large grocery shopping; Fernley perishables groceries.
With all that, I think we did pretty good to average more than 30 MPH.
Now I need to unpack and maybe get some sleep once the air conditioning manages to cool our trailer down to a habitable temperature.