Elaine leaves tomorrow with her brother and his wife to do a Viking River cruise Bucharest to Budapest and then they fly to Prague where they have booked an apartment for a week. They're flying Air France via Paris to Bucharest. They did want to do it in September but the cruises were all booked. It might be a bit warm but I'm sure everything will work out fine.
Sounds like it's going to be a wonderful trip!
http://www.vikingrivercruisescanada.com/cruise-destinations/europe/passage-eastern-europe/2016-bucharest-budapest/index.html
Osuek, Croatia
Belgrade, Servia
Bucharest, Romania