This is more of an intellectual thought exercise as I know butterflies would mean lots of other differences. However if we can assume those butterflies are somewhat restrained (I know, I know) and that we get to the mid-20th Century with a Europe that is exhausted by war and now mainly liberal democratic but with a Germany that is much bigger than OTL. E.g. one that includes the Eastern territories, Bohemia, Austria and a somewhat Germanised Cisleithania.
Is an alt-EU - defined broadly as a voluntary coming together of democratic states in the name of shared values and peace - possible with a Germany that is so powerful? Or is it just too unbalanced to work? Again, imagine this Germany, while large, is democratic and committed to peace.