Well, even if we had won quickly, the Entente powers wouldn’t have been kept down for long. They were much mightier in the long run than the Central powers.
The best option would have been to ask them to accept the status quo ante. Still I believe Austria-Hungary’s end would have come anyway, after the death of Emperor Francis Joseph - unless his successor would have carried out the far-reaching reforms of Francis Ferdinand.
But in real life, i.e. with the war still raging in 1916, when the old Emperor died, this was out of the question - just as the plan for Irish Home Rule had been suspended in 1914.
I suspect all that is correct.
My formulation of “Let the Kaiser keep it” is just a shorthand to stay out of Europe’s wars.
For the Anglosphere especially, WW1 was personalized as “Against the Kaiser”. etc.