I would think that with all the malls that have died in the past decade and remained vacant, there must be a lot of empty parking lots that some enterprising film impressario could convert into a temporary pop-up drive in theater.
Around where I live, the two drive-ins that have appeared are located on idle farmland.
What probably will most prevent a drive-in renaissance, though, is that the studios are holding back the release dates of their first-run films until traditional theaters can began to fully operate again.