Ask yourself some questions....
Why exactly whould you stock up on propane this way? Why would using a 20lb tank be a problem? Do you plan to grab your stove and run like mad with it on a regular basis? Do you think it will be more portable? If so how will you carry 10-20 bottles?
Either way you'll have just 1-2 with you if you need to move quickly without a vehicle. If you have a vehice loading one tank vs several armfuls is much easier. Once I set my stove up I don't move it, same mostly for my lanterns. I doubt most people holed up in their BOL will be dismantling their equipment often.
It's a bit silly to be honest. If you plan to use it for lanterns or need some propane for your BOB then buy a couple of bottles and a refiller adapter. Buying in bulk saves your money for other preps, propane is no exception.
I found an adapter hose for $5 on clearance at HD, and the 20lb tanks are $19 for a refill and $45 for an extra tank at HD. At $3 for 1 lb it will cost $60 to buy the same amount in 1lb bottles, not to mention all the extra space 20 bottles will take up vs one tank and a 6ft hose.
Smarter, not harder!
