FWIW, someone's just reminded me that there is an alternative.........find an old, probably non-flying, large, piston aircraft and park it, full of fuel, near your hangar. Adapt the fuel system to provide a filtered output to a filler hose instead of an engine. Fill overwing from an Avgas road bridger vehicle when required.
Hmmm.....OK, there are a few minor details to overcome, but nothing's impossible if you have the will and an open mind, and at least you would be sidestepping a host of expensive regulations.
A DC 6 or DC 3 would be best; from bitter experience I know that even a Percival Prentice carried 80 Imp Gall/360 litres (400 miles range max!); there are some rotting on airfield graveyards. And I'm sure there are some old twins that would hold more than that; as I recall the Piper Aztec I once flew held about 150 USG. If you can get an airworthy one you could simply fly it somewhere to fill up, if there's an airfield supplying Avgas reasonably close.