Painting the envelope with solid rocket fuel didn’t help much. However, I remember that the Space Shuttle had to have its hydrogen tank topped off constantly during the pre launch procedures, and could only stand fully fueled for a few hours at most.
Why the shuttle had to refuel for boiloff, rocket has to weigh a specfic amount at launch. Any extra fuel and insulation becomes useless payload. Boiloff or leakage of hydrogen in a fixed envirment is less than 1% per day when dealing with metric tons of the stuff in a fuel bunker.
Electricity that is stored short term has a true cost of zero, solar, hydro, wind, nuclear, conventional spenddown it would otherwise never be available. Fuel Cells are just another form of advanced battery dont get stuck on the chemistry or the need for supercool density.