At the moment if you would like to bootcamp it Microsoft is offering a completely free download of Windows 10.
I'm pretty sure you need to pay maybe 1 year after you donwload the free version, and stuff like network settings are locked in the free version which is dumb. That said, if you are gonna bootcamp anyways, do linux mint or something else. It seems linux will get supported in the near future and is easy to setup, so you might as well just do that instead.
You can get it at :https://www.microsoft.com/en-us/software-download/...
When I use it for virtual box or dual boot my system there are no problems for me and it never even asks if you want to upgrade or if you have a key. I hope if you choose this it works.