I always release snakes back as close to the very same place I found them. I think it's important because they do use scent left by other snakes to find their way back to the den. (and then there's the gene pool issue) In other words, if you release the snake where you found it, there is no "finding a hibernation spot for the winter". They already know where to go! Then it's just a matter of releasing them while there is still sufficient warm days left for them to be active enough to get back to the den.

But as far as "to release or not to release" goes, if you're getting snakes from an area where they are plentiful and your snake is not any rare morph or anything like that, then don't bother with the ones that are fussy and don't adapt to captivity well. Just try out different snakes and only keep the ones that adapt well and aren't fussy. Better for the snake, better for you. However, if you really have your heart set on a specific snake and it's being fussy, often deworming followed by a dose of probiotics can make a huge difference in their attitude towards the foods you offer.