Except single-payer was never a component to the ACA. It was removed early on in the negotiations because Republicans outright rejected it, and the Obama administration and congressional Dems wanted a bipartisan bill.

Now the GOP controls Congress and the WH. They're still not going to accept a single payer option, but that doesn't mean there can't be compromise by moderates that would fix the ACA, and bring Dems to the table. The extremists on both sides wouldn't like it, but it would be effective and get something passed.