Vienna in late January is quiet, cold, and entirely worth it. The holiday crowds are gone, the palaces like Schönbrunn have room to breathe, and you can spend hours reading a book inside a wood-paneled coffeehouse without anyone rushing you out.
A typical week-long trip runs around $2600 once you factor in flights, a decent hotel, and daily meals. Spreading that cost out over time makes it easier to swallow, but you need a clear plan so you aren't paying for last month's strudel a year from now.
That 0% intro window is a strict deadline, not free money, so make sure your math checks out. If any part of the $2600 balance is still sitting there when the 18 months are up, deferred interest or standard rates will kick in on whatever is left over.