I've never coddled snapdragons, grow them every year and they do very well. I got heat mats a couple years back but discovered that if I used them in any east or south windows the plants got too hot, even turned to the lowest setting. I even changed thermostat controls, but still happened. So not planning to set them up, this year. We will see...
I like how you used the word "coddled," I can just see your snaps snapping to attention and growing cause you told them too lol!
I only got the heat mats for the hard to germinate flower cultivars that I wanted to try, I've never had an issue with any of my veg, it sounds like your windows do the trick just fine!
!PIZZA
!BBH
They seem to, at least those 2 directions. But I do have heat mats for the other windows.