I believe there are Windows 7 drivers for RTX 3xxx series out there that work. LTSC 2019 is pretty good, installed it on two Thinkpads (e485 & e14 gen 2) and this 12 inch dell convertible with a 7th gen core i7 I'm typing on right now
I am using the 474.11 Nvidia driver for Windows 7 on my Windows 7 x64 installation with RTX 3060 Ti and it works fine there. I also use the 475.14 Nvidia driver for Windows 7 (requires a patch from canonkong) on my Windows Server 2008 R2 installation with RTX 3060 on my second computer and it also works fine there. And yes, LTSC 2019 / Server 2019 are good, and I will continue to use them for the next several years, if not longer.