My husband just handed me A Nervous Splendor by Frederic Morton. Haven’t read it yet, but I’m about to.
One of my all-time favorite history books. In fact, one that inspired me to enter the history field. It is non-fiction; however, it reads like almost like a novel. Think Devil in the White City. Morton wrote a second book called Thunder at Twilight that wasn't as good, but would still be an interesting read before traveling to Austria.
On the off chance you are a lover of fantasy and historical fiction, there's the second book in the "Athena Club" series: European Travel for the Monstrous Gentlewoman. Absolutely silly, frivolous, fun historical fantasy for those that love the genre. Ignore this paragraph entirely if that doesn't apply to you!!
Finally, I haven't read it yet, but I've heard good things about Stolen Beauty by Laurie Lico Albanese. It is on my list..