Windows bootcamp external ssd

Hi. Is there a way to make windows work with Mac mini on external ssd ? The reason I want to do that is that I have 128gb disk on Mac and once I install Windows on it, there is no free space available for anything so that's kind of pointless. I managed to install windows on ssd but onceI boot from it. Windows logo appears and Mac shuts down. Nothing happens. Any suggestions will be appreciated.

Thank you.