I don’t know if this solves your problem already, but you can as felixchenier mentioned just drag your note out of your obsidian instance and it opens in a new window.
Same is possible if you use the comand pallette (CTRL + P) and select “Open current tab in new window” or “Move current tab to new window”
Nevertheless:
I love the aforementioned capability, but what I am rather painfully missing is the right sidebar, so that I can see e.g. back links and outgoing links right next to my newly created window.
(I don’t care about the left side bar as much)
Maybe you, too, are missing that functionality?