Chrysalis in temp low 50s

I live in suburb Buffalo NY. I was not expecting having 4 Monarch caterpillars after years of planting a swamp milkweed. There are common milkweed around but they barely fed on them. One stayed right next to the swamp milkweed on a small goldenrod stem. I protected it from rain and strong wind. It’s been 18 days and the chrysalis is half blackened. There’s been a brown spot on one side very early in the process. The temperatures during the day are in the sixties and low to mid seventies. It won’t last though. I read that it will die. I have no experience and not equipped to bring it inside. I went from overjoyed to heartbroken. I don’t think there’s hope. Thank you for reading.