Windows 10 doesn’t actually need to be activated to receive security updates. You’ll just deal with an annoying watermark in the bottom right all the time. IoT may be different, though.

Regardless, I recommend taking a look at this project: https://massgrave.dev/

Consider running the LTSC version. It gets extended support.

You can give a man a drink and his thirst will be quenched for a day, but if you show a man to the water source, he will be quenched for the rest of his life.