If you use a Microsoft online account to sign in to Windows, and you have enabled PIN sign-in (which is confusingly considered to be part of "Windows Hello"), then you will NOT be given the option to sign in using a password, and clicking the "I Forgot My PIN" link will do NOTHING.
If you do manage to finally get signed back into your PC, there is a critical setting you must DISABLE to prevent this awful situation from ever happening again. Microsoft, in their infinite wisdom, stupidly ENABLES the setting by default.
Settings >> Accounts >> Sign-In Options:
"For improved security, only allow Windows Hello sign-in for Microsoft accounts on this device (Recommended)"
You must DISABLE that setting! Then the next time this happens, the login screen will actually give you the option to sign in using your password.
Also, this is clearly caused by the PC suddenly losing power while in hibernate. Windows somehow wrongly detects that situation as an incorrect PIN being entered too many times. This is a Windows bug that desperately needs to be fixed. And Windows lock/login should not stupidly suggest using an alternate sign-in method when the setting described above is ENABLED. And that setting should also not stupidly default to ON when enabling a PIN on a Microsoft account. Multiple layers of epic failure here... which might have been caught via manual QA testing, if Microsoft hadn't laid off all their testers years ago.