On Mon, 30 Nov 2015, tim..... wrote:

Replacing the Milano-Wien leg with a sensible day option is possible

If you want to avoid the OBB EC bus replacements,
there are a couple of FUC day trains from Udine to Villach (707 and
1717) where you can connect to the Austrian network. And apparently
there is also a true EC train (EC 30) from Venice to Udine (1742) and
Vienna (2327) but it will travel in the dark.