Can't promise you an easy and fast victory.
How about the Ottomans living up to their promise and coming through Hungary with a big army? The PLC can be more or less neutralized by a smaller force of the Ottomans and Crimeans. Of course, promised 400,000 Ottomans was a pure fantasy on Sultan's part but 50 - 60,000 (of which 30 - 40,000 would be high quality troops) plus the Hungarians could a serious business, especially when the Bohemian troops had been closing on Vienna.
OTOH, when you are getting the Ottomans involved, you have to keep in mind that their logistics was rather cumbersome: unlike their Western contemporaries, they had been paying a very serious attention to the regular supplies of their troops which means that they had to carry with them huge baggage train. Anyway, if troops of the Unholy Alliance

evilsmile

are converging on Vienna then, even if Vienna itself is not captured, all the Catholic forces are going there. Unlike the OTL 2nd Vienna, the German Protestants are not joining the Catholic forces because the Ottomans are acting in concert with the Protestants (BTW, Bohemia, IIRC, was not formally a part of the HRE even if its king was an elector but let it be). With some of the Hapsburg hereditary lands also having numerous Protestants (and rebelling), the Austrian Hapsburgs and the Holy League are on the defense for a near future. If the Dutch are breaking peace a little bit ahead of the schedule (don't remember what was left out of the agreed upon time), then the Spanish troops in the Netherlands are tied as well and the all hope is on the reinforcements coming from Spain and Italy.
.