Well, I too have been down this road and I am glad to see you are willing to "fix" them and return them to live their life...
My sister, who lives in Lake City, FL, has had many cats dumped on her. They have lots of acreage and they seem to find her house..she fixes them and finds a home for many but now, the number is up to 11.
My vet here in Alabama told me that the feral cats would survive outdoors for about 2 to 3 yrs as the winter's are hard on them.. I fixed many, turned them loose as they were past domesticating, and would also put out dry food for them.
Too bad people don't find it in their heart to fix their animals...
I am proud of anyone that takes the time and effort to trap and fix a feral cat.