If you're keen you could buy a used laptop on eBay or Gumtree that comes with Win7 and just use it for tweaking the Mini - when Win7 conks out in 2020 just turn the WiFi off & keep using it. I've found Lenovo Thinkpads to be reliable as used systems - the 12" "X" models are great for portability, noting they don't have a DVD drive.