I'd put that more like 99.9999% chance he'll win. He's already won. The audit would have to flip multiple states to change the outcome, and in the swing states he picked up he has leads in the 10s of thousands. The odds of him losing now are in the "struck by lightning" range. There certainly isn't a 1/6 chance he's going to lose now. Those odds are valid to contemplate before the election, because polling is never 100% accurate, but once the actual votes are in, it would take a miracle to change it.
Some of the lawsuits involved for example 53 improperly filled-out ballots, and that's for a state where Biden is up by 12000. They'd have to come up with 240 identical lawsuits and win all of them to change the outcome. Lawsuits like that aren't seriously intended to change the outcome through review, they're purely for the optics to create doubt in the mind of the Trump loyalists who lap that stuff up. Like the QAnons, those people just go "there's a lawsuit so it's a thing" rather than actually reading the actual content of the lawsuit and realizing it's bullshit.
EDIT: as for the fake votes things, it's just silly. To do it on that scale without there being any obvious anomalies, there would have to be literally tens of thousands of people involved in this conspiracy, all slipping individual ballots into the stream none of whom ever blabs and none of whom ever fucks up. It's basically impossible that this could happen like that. Conspiracies that involved a handful of people get fucked up because someone gets drunk and blabs or boasts about it to someone else, and the coordination to do this on a national scale with thousands of participants without any trail of records, calls, emails, texts, is just impossible too.
EDIT2: Think about it this way: to pull this off (and in 2016 when Trump claimed it happened too) and leave no visible record of anything amiss would be an absolute work of genius, using completely unknown novel means of faking an election that only those people know how to pull off, carried out by thousands of people scattered around the country in complete control of the process, with absolute discipline and loyalty and perfect execution without any fuck-ups (lost phones, misdirected emails, overheard conversations etc), leaks or whistle-blowers - and there's a $1 million reward for evidence of voter fraud on offer, so complete loyalty and refusal to take the money - even under the eyes of Republican state apparatus in some cases. And ... this is the Democrats you're talking about. Highly organized super genius masterminds apparently. They do a great job of hiding it the rest of the time. Point being: even if it was theoretically possible to pull something like that off (which it probably is not), clearly the Democratic campaign organizers are not capable of doing that. Adding a third person to a secret plot is usually enough to derail things. Conspiracies that involve thousands, or entire classes of people (such as the theory that doctors made up Covid to get more money) are just nonsense. This election fraud thing is on the level of the moon landing hoax theories in terms of plausibility.