"Don't forget about a many many way split
of the jackpot, at that time, too."
The upside to $2 tickets and the ridiculous odds of the new matrix are that there's a pretty good chance of a single winner even when the cash value passes the $300 million mark.
There has never been more than 3 winners for a PB or MM jackpot, and there have been 3 winners only 3 times. The MM jackpot that still holds the record for the largest cash payout ever was the first time. The other 2 were for PB jackpots (the 2nd and 5th largest cash payouts). The 3rd largest cash payout went to 2 winners, and the 4th went to a single winner. All of those were with a number of possible combinations that's relatively small compared to the new matrix.
With the new PB matrix multiple winners will become less likely, and even for a very large jackpot there will be a pretty good chance of a single winner. The MM record jackpot also holds the record for most tickets sold for a single drawing, at 652 million. That's almost twice as many as the 2nd highest number of tickets sold, which is 336 million. Those sales were in 2012 and 2013 long before the sales slump that spawned the most recent PB matrix came along. The largest jackpot in the past 2 years was last February's $564 million PB jackpot, which only managed a relatively meager 190 million tickets.
Based on recent sales it will probably take a jackpot of at least 600 million to get into that sales territory again, and with the new matrix 200 million tickets would only cover 2/3 of the possible combinations even if there were no repeats. Of course at that level there are many millions of repeats, but the chances of having 3 winners is still fairly modest. Unless you think that 3 or 4 is "many, many winners" the chances of that are essentially zero. Even if the jackpot gets insanely large and sales hit 500 million tickets anything more than 3 winners is still fairly unlikely.
As far as selling all possible combinations goes, that's a statistical improbability until ticket sales are about 5 times the number of possible combinations. Under the new matrix that means it's very unlikely until 1.5 billion tickets are sold. As a rough guess I suspect we'd need to see a jackpot of at least a billion to roll for a frenzy that big. If it did happen it would bump the cash value by over 900 million, for a total cash value of more than $1.5 billion.