I haven’t ever gotten them to re-bloom on purpose. I just keep them around for years and periodically they do. Some re-bloom much more often than others. I got a few orchid books out of the library recently to take a more informed approach. It seems like many different factors can influence re-blooming and that it depends on the genus/species. Temperature changes like you mentioned, also day length, amount of light, even pressure changes with the weather! Good luck with your orchids.