Given their limited offensive actions during the trench warfare, the Austro-Hungarians were surely considering this was as far as they could actually advance. Didn't they put up negotiation positions through third parties before Versailles?
From what seems to be a pretty analysis, run by German universities, it looks like there were essentially no peace attempts.
After the Brest-Litovsk treaty it seems that Ludendorff really thought the war was winnable. The provisions of the treaty, far harsher than Versailles, really could have made a difference for the German domestic economy if there were a functional Russian state to meet its obligations.
The Spring Offensive of 1918 seems to be pretty clearly an attempt to capture Paris before the AEF could get established. On top of the limited documentation I think this intent shows there was little interest in a settlement.
The entire time, from 1914 to 1918, both sides tried to impose a victor's peace on the other side.
Germany didn't sue for peace, but they did talk of peace a lot on their terms, as did all the other major combatants.
In fact, insincere peace discussions never really stopped. But that was actually what made this war so revealing of the cultural norm of the participants. The negotiators on all sides routinely made demands that the other side could not possibly accept based on the latest news from the front.
And it went back and forth like that for years.