My quick reaction:
Democrats have only one more opportunity this year to use the reconciliation process to turn their sprawling policy agenda into reality. This is why Chuck Schumer, the Senate Majority Leader, appears resolved to pass the bipartisan infrastructure agreement first, and then use the reconciliation process to ram through the White House's American Family Plan.
It sounds simple enough, so what can go wrong?
Schumer is under pressure from the progressive wing of his party to include the climate change measures (excluded from the bipartisan infrastructure plan) in the budget resolution that will go through the reconciliation process. However, if the Republicans suspect this is his game plan, they will likely pull their support from the bipartisan infrastructure deal. Even Trump came out this weekend warning the GOP against being "played" over "fake infrastructure proposals".
What this means is that not only it will be very difficult to pass the two bills separately, but Schumer will need the GOP to sign off on what he is going to put through the reconciliation process if he wants to pass the infrastructure deal!
In game theory, this is called a dynamic inconsistency problem. There is no obvious solution. I would not be holding my breath that either bill gets through before the winter.