How long do drones live?
About three seconds after having it chopped off! :-D
I think the evidence is that queens fly about as far as they need to mate. In feral colonies, that might be a good distance to a DCA with drones not her own.
But in bee yards with multiple hives, The best solution to take away any chances problems with drones, is to have two yards with different genetics. then you take a graft or cells from one yard and have them breed in the other.
Most of the problems if you were to even experience them to begin with, are when a beekeeper just sits with a few hives, and has no resources to really breed queens. So you either raise them at a buddies place, move in eggs or grafts from another location, etc.
I really think the backyard beekeeper raising one or two queens will not have much problems. You are not flooding the area with your genetics, the feral population and genetics pool is probably vast enough to support healthy queens, and much is to do about nothing.
Most of these problems are created by the so-called "queen producer" who has the same genetics in every hive (Like after dumping in 20 packages in 20 hives all at the same location), then raising queens while grafting from one of the queens. He is not doing anyone service by this model and will produce the weakest queens.
Raising one or two queens...I would not sweat it. Raising 20 queens with two or three cycles per year and selling these off as "quality" queens....then do the right thing and do what is needed for success. Use different yards with selected genetics, use drone saturation colonies, etc.