The reason your Monarch is shivering is because it is cold that is how they warm up. They can fly at temps above 50 degrees. I actually saw one flying over hawk ridge in PA when the temp in the parking area was 37 degrees.
viewtopic.php?f=11&t=1669#p7769This is information I posted earlier on how low they can go.
If you use the search feature above right, you can access tons of info on how to feed them and what to use.
I have about 15 Monarch pupae. I think I will have to try to get them a ride down to Virginia beach. We've already lost most of our annuals to frost her in my area. I have them inside. As long as your indoor temps don't go above 85 they will remain in diapause.