The 12th Amendment is pretty clear that the senate certifies whoever has the majority of electors, which would be Biden unless that is reversed.
As for the suits making it to SCOTUS, my understanding was that the justices selecting whether a case is heard by district --- that this would only happen if a given suit is appealed to the SC for a review in the first place. So far only 1 PA suit has managed to take it through two denial-appeal cycles and is on its way. Nobody knows if the others (GA, MI, WI) can be appealed to the SC in time for a Dec 14th vote. I don't even know if they have had a hearing yet.
But wouldn't the SC need to toss out 37+ electors to make it go to the House for a vote? And even this is entirely dependent on whether the PA, GA, MI, and WI suits make it to the SCOTUS for a hearing BEFORE Dec 14th. Not to mention 3/4 of those would have to pass.
As for where the suits stand now, I don't think anybody knows if they will make it that far.
My concern is that we don't know where the PA, GA, MI, and WI lawsuits stand, or if they will be heard by SCOTUS before the 12/14 deadline. Or even before Inauguration Day. There is historical precedent for the 1876 election being decided 3 days before Inauguration Day, but I don't know the legal part of that.
I'm down