We recently took the train from Vienna to Venice via Innsbruck but would NOT do this again. It's a long trip, and the scenery was disappointing from Innsbruck to Venice. The Brenner Pass is one big truck stop with an outlet mall.
And a train trip directly from Vienna to Venice requires a ride on a bus to the border of the countries. It's just too bad there are no budget European airlines linking the two cities. Flying is expensive.
And the trip is pretty far @ 360 miles per driving.
We chose this option because we didn't want to be on the bus...............all part of the learning adventure.
I just did almost the same trip, from Vienna to Udine. It snowed from Villach for about half an hour. It was May 25. Train was okay but the bus...