There is an actual probability, given the 9/11 physical collapse, that she is having physical trouble again. That changes the analysis.
She can’t go on, but she can’t not go on.
Which is worse, to be seen collapsing on national TV or to be heard complaining that something wasn’t fair?
I think Team Clinton will roll the dice on her being able to make it through the debate, using whatever combination of drugs is required.
You sum it up well: she can’t go on, but she can’t afford not to go on.
Her only hope is for a haymaker in next week’s debate.
And, at the risk of sounding like a charter member of the Tinfoil Hat Club, don’t rule out some sort of Wag the Dog scenario that might prompt cancellation or curtailing the rest of the debates. These people will stop at nothing to gain/retain power.