Unless you have Windows-only apps that have no open source comparables, moving to Linux or Android is an option, and a cheap one. If a new machine is in the budget, there's also Mac.
Windows 7 is still available for purchase, but it appears that this includes only full-install products. The Upgrade products aren't listed at Newegg, for example.
I have legacy Windows apps, and elected to build a new PC based on an AMD APU, running Windows 7 Pro 64-bit, with XP Mode for the legacies. Once installed, networking will be turned off inside XP Mode to protect it.
XP Mode (which isn't supported on Win8, by the way) probably won't be available for download after EOL day. You have to have Win 7 (Ultimate, Pro or Enterprise only) installed and activated to get XP Mode. Installing XP Mode is challenging, esp. on AMD, which requires a hot fix. Installing XPM on Intel might be impossible, as their low-end stuff often has the necessary VM logic fused off.
Agree with all your advice except this ...
> or Android
Android is a Google product. It is spyware masquerading as an OS. I would have absolutely nothing to do with it. I don’t have a “smart” phone, either, because I would have to choose between two fascist companies, Apple and Google. No.Thanks.