Looks like a great trip in the offing. For the London to Ljubljana leg consider the “Romantic Road” down through Germany. You will visit many beautiful cities and towns, starting in Wurzberg, via Rothenburg ob der Tauber (think Chitty Chitty Bang Bang), down to Fussen and Schloss Neuschwanstein (think Disney Castle - its true Walt Disney modelled his trademark castle on this place !) - a great place to visit. From there head for Innsbruck and then choose a route through the mountains to Villach. If you have time, visit Lake Jasna - beautiful. Also just along the road is the Planica Nordic centre with huge Ski Jump slopes. In the summer they rig a zip wire from the highest one - you know you want to do it. ! From there to Ljubljana it is an easy drive - look out for the visible evidence of the tragic fighting in the wars with Croatia/Serbia etc. Ljubljana is a great city - worth getting the bus up to the castle and strolling back to the city. Slovenia is a beautiful country with very friendly people. Lake Bled is beautiful but very touristy. Lake Bohinj is stunning and not too far off your track. If you go into Croatia, (slightly more “edgy than Slovenia) but no real issues), the cost and the islands are wonderful. Zadar is beautiful, dont miss the “Sea Organ” - totally bonkers, and the Colosseum in Pula is very impressive.
