Even if there's just a 10% chance that the floodgates open and give way to a Democratic landslide*, I think she's got to prepare for it. If she can win back the House and strengthen the majority in the Senate, she'll have the potential to become one of the most consequential presidents of her time. She's not going to want to squander the opportunity to make those conditions happen.
*"landslide" meaning something really yuge, beyond even '08ama.
It would've been nice if we got Hillary in 2008 and Obama in 2016. She would not have squandered many months of a massive Democratic majority in Congress by playing footsie with McConnell. Too bad.