" Two of the plants are still growing strong. Snapdragons are annuals. Not sure if I've gotten lucky, the laziness in me of not cleaning the bed is enough of a mulch to protect the plant, the lack of a heavy deep snow (despite subzero temps), or if the plant is a genetic mutation and is now both capable of surviving our winters and mind control. "
I think my zinnias practice mind control over me. But you may be on to something with those snaps. You very well could have a good mutation there, with the promise of getting the best of both worlds between annuals and perennials. Annuals tend to bloom all season, whereas perennials tend to be "one shots". A perennial that blooms all season would be something. If I weren't breeding zinnias I might be breeding snaps. They come in a wide color range like zinnias, including bi-colors, and both double and single flower forms. You could cross your mutant snap with them to get a whole strain of new ornamentals. Snapdragons are currently available in a very wide range of strains.
Amateur plant breeding can be a fascinating hobby. To show what is possible, these are some of my zinnias that are not available in seed packets.
I have been concentrating on new flower forms in zinnias, but a perennial one like your snap would be a real find. Plant breeding can be a fascinating hobby.
ZM (not associated with any product or vendor mentioned or linked)