Rick - The worm eggs do wind up in the castings compost that get spread around in my garden. So there probably are red wigglers in my soil, but they don't live long outside the bin. I don't compost as much around my plants as I do in the bins because of rats and raccoons. So they would likely starve in my sandy and organic-less garden. Which is why I am adding castings to my soil, to amend it and hopefully improve it over time.
Cindy - I agree. They do slow down considerably (even here in FL) in the Winter. They are most active right now and have multiplied at quite an amazing rate during the warmer months. I have my worm bin on my screen porch (so critters can't get into the bins) and they are shaded from the sun and heat coming off the ground outside the porch. It works for me ... and my worms. I do have leaf mulch down around my garden beds and the worm eggs might hatch and eat that leaf litter to stay alive. If that is the case, they should last a while as I have quite the pile of leaves in every border bed in my yard. It cuts down on weeds in those beds. (I have 2 oak trees that produce a lot of leaf litter every Winter!) I am sure the escapees would miss the buffet meals in my bin. They get quite the variety from food waste!
