I read about indoor wintering on a commercial scale in "The Hive and the Honey Bee". According to the book, this is a common practice in Canada. Does anyone here have any experience with large scale indoor wintering? I currently migrate my hives to the south for the winter, but this is getting more expensive each year. It seems to me that a building to winter in would "pay for itself" in just a few years in transportation costs savings alone. Being in central Wisconsin, the concept seems to have merit. I realize most going south are also sending their bees to California for almonds. I'm looking to winter the bees here in Wisconsin, and forgo going to California. The idea of getting sprayed in California, like others I know, or spreading pests and diseases to my hives outweigh the dollars. We are a growing business looking to grow to the 1000 hive mark. Outdoor wintering, and the annual mortality rates associated with it are not acceptable to me. Thanks for any input you may have.