2019 Summer Plan

I am planning for our Europe summer trip. It has been decided that we will fly from USA to Frankfurt, Germany, visit Prague/Vienna/Budapest/Croatia/Istanbul or any combination of them, and leave Europe from Istanbul for China. But there are two options for the routes inside central Europe, that we are still debating. The options are:

Option 1 (with Budapest):
Drive: Frankfurt - Heidelberg - Prague, Czech - Cesky Krumlov - Budapest - Rovinj, Croatia - Zagreb, Croatia - Vienna
Fly: Vienna - Istanbul (Stay for 3 days) - Beijing (Stay for 3 weeks) - USA
This route is 2415 km long, and I think it is kind of too rush.

Option 2 (Skip Budapest):
Drive: Frankfurt - Heidelberg - Prague, Czech - Cesky Krumlov - Vienna - Rovinj, Croatia - Zagreb, Croatia
Fly: Zagreb - Istanbul (Stay for 3 days) - Beijing (Stay for 3 weeks) - USA
And this route is 1782 km long, more than 600 km less than Option 1. But we will skip Budapest, and spend more days in Vienna with this route.