tfouto that's not a concern right now. The MyDigitalLife forums have a patch that allows you to install ESU updates from Microsoft right over Windows Update, and it's literally a 1 click install. So it's still perfectly secure. Pair it with any decent AV software and you will be good to go for at least 3 more years. Not to mention the days of "hackers" trying to attack PC's is pretty much ancient history. There's no money in that. All the money is in browser malware and spyware and using Trojans on web pages to deliver payloads. Having a secure browser, and practicing safe browsing habits, is 99.99% of staying secure.
I would recommend never moving to Windows 10. Microsoft has continually shown how committed they are to retaining control over the OS and pushing through updates and changes without any notice and no way to back them out. Any one of those could render your PC unusable. If you are blocking Windows Updates on Windows 10, you are just as "unsecure" as not updating Windows 7. Not to mention the UI is simply atrocious,
Windows 7 can be run on any new hardware, it's just a matter of getting the USB 3.0 drivers added to the installation media, there are plenty of YouTube videos on how to do it. Or you could install Linux on the new hardware and virtualize Windows 7 on it. That gives you even more flexability to make hard drive back ups you can revert to whenever you like so you always have a "safe state" you can return to with one click.
Long and short of it is there is zero reason to abandon Windows 7 if it works for you. I have yet to find a single software program that requires Windows 10 to run, and I'm running all the latest editions of Chrome, Cerberus FTP server, Photoshop, Plex, Discord, Steam, etc etc.