The expansion factor is why I like to buy fuel in the morning on road trips. It does expand a little more than 1% with the temperature difference. Depending on the tank volume will depend on the amount expanded, however, 17 gallons of fuel would expand to about 2 1/2 cups worth.
If you do top it off to the bottom of the filler cap, then I would recommend driving the truck a bit to use up a bit of fuel.
I also suggest you look at the cap like Woogeroo mentioned as your seal may be gone.
