So to say, this whole deal of SEC_ERROR_EXPIRED_CERTIFICATE blocking access to the entire page is really dumb, and needs to be given the option to allow a particular exception or another through, without allowing or denying all.
For an example, I went to access a site today whose certificate expired in LESS than twelve hours, and in an ideal world that would be given an exception.
I'm pretty sure you could at least do like Microsoft Edge and allow us to continue to the page: