I seem to recall that Google pays out all account balances at the end of the year even if they are below $100
No, they do not. They are carrying my $89.17 and adding $0.97 or so a month since I have removed most AdSense a few years ago. Since I personally knew a few people whose accounts were closed without dialog and because they insist on running images in text-only widgets I removed the ads from all but one little site. One day maybe I'll get around to creating more widgets and finish off that amount but while they sort out mobile and other things I'm better off waiting.