WI Vardar Offensive Fails

How could the Vardar Offensive in 1918 have failed, in such a way that the Bulgarian Armistice is delayed by at least a month? (Maybe the Bulgarians decide not to make a stand at Dobro Pole?) In Germany, would this change Ludendorff's thinking, and delay German peace feelers and civilian government changes as well? And does the Western Front go as OTL in this time? If so to all, could the Allies have marched onto German soil before an armistice could be reached?
 
How could the Vardar Offensive in 1918 have failed, in such a way that the Bulgarian Armistice is delayed by at least a month? (Maybe the Bulgarians decide not to make a stand at Dobro Pole?) In Germany, would this change Ludendorff's thinking, and delay German peace feelers and civilian government changes as well? And does the Western Front go as OTL in this time? If so to all, could the Allies have marched onto German soil before an armistice could be reached?

Question 1: How to change the outcome of the offensive. Not making a stand at Dobro Pole would likely delay the rate at which the Bulgarians were collapsing but they would still collapse anon.

Question 2: Does this delay German peace feelers? At most 3 days. They were also collapsing at this point.

It would actually make more of an impact on the Ottomans. It was the Macedonian Front not Palestine and/or Mesopotamia which forced them to seek an armistice because it meant Constantinople would soon become besieged.
 
Question 2: Does this delay German peace feelers? At most 3 days. They were also collapsing at this point.

Hm, doesn't seem like much. But then again... I've read that at the Second Paris Conference (October 29 to November 6), the Allies almost reached an impasse, which might have dragged out negotiations. If that also adds a few days, that might delay the Armistice by a week or so; as bad as things were getting there, would that give the Western Offenses enough time to reach the German border?
 
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