Some things I just heard on TV from Dennis Dodd, CBS Sports, that sheds more light on this proposal. (bear with me, as I've edited this as I learn more)
1. The automatic bids would go to the 6 highest ranked conference champions. That does not guarantee all Power 5 champions get in. Last year, for instance, the 6 highest ranked conference champions were: Alabama (1), Clemson (2), Ohio State (3), Oklahoma (6), Cincinnati (8) and Coastal Carolina (12). Oregon, the Pac-12 champion, was ranked 25th and would not have gotten in.
* Obviously citing last season comes with the enormous caveat of COVID's impact, especially for the Pac-12 who played the fewest games, and Oregon not even winning their division but getting to play for the conference title because Washington couldn't play.
2. That does potentially open up more opportunities for G5 teams.
3. The Top 4 seeds, and the byes that come with it, would go to the Top 4 ranked conference champs. So Notre Dame, an independent, could be seeded no higher than #5 regardless of overall ranking.
4. The "first round" games would be played on campuses, with the higher-ranked teams hosting. The quarter and semi-finals would be incorporated with existing bowl games. The championship game will remain independently hosted at a neutral site.
5. As far as dates, the first round would be sometime in the 2-weeks following the conference championship games, which are typically the first Saturday in December. The quarterfinal games would be played over 2 days sometime during the New Year's window, depending on when Sunday (NFL) falls. I haven't heard anything yet about the semifinal games, but I would think they would want to do it on the Saturday of the NFL's Week 18 (taking advantage of the added game), otherwise they might have to go to weeknight matchups to avoid overlap with NFL playoff games, which would be the kiss of death for TV ratings.
6. This could happen as soon as 2023, two years before the current CFP broadcast contract runs out. That means ESPN would have exclusive negotiating rights to broadcast the entire expanded Playoff (they'd probably shoot for the moon anyway, even if they didn't).