I'm trying to plan the Croatia portion of my 2-month Europe backpacking trip. Originally I was going to skip Dubrovnik and take the overnight train from Bratislava to Split (3 nights), then do Zadar (3 nights), Plitvice lakes (2 nights) and Zagreb (3 nights) to then continue on to Slovenia. However, now I've heard this train might be discontinued and regardless I've decided it might be smarter to fly from Budapest (where I'll be before Croatia) to Dubrovnik as it's the same price or less as the 14.5 hour overnight train and probably a quicker experience (although there is a 3h layover in Belgrade, so not a ton quicker).
Now arrives the dilemma of trying to fit another city in my tight schedule. How would you fit Dubrovnik, Split, Zadar, Plitvice and Zagreb into 11-12 nights? Is it doable? I definitely do want to see some islands but just as a day trip as I don't want to add even more places to sleep in (plus honestly the logistics of checking-in/out, carrying my bags for just one night and an early check out gives me anxiety lol and accommodation there are usually not cheap). Which is why I'm also reluctant in reducing Plitvice to 1 night, although I might not have a choice. I feel like if I don't stay long enough in the cities, day trips to the islands (or other day trips) might also not be possible too.
I also don't want to remove Zagreb (I know it's not the most popular) since I'm interested in it and also will be going to Ljubljana from there after. The reasoning for more days in Zadar although it's smaller was that the hostels are a lot cheaper so I can enjoy relaxing beach days and potential day trip for cheaper (split is double the price).
Any recommendations? I won't have a car btw, so it will be all by bus. I'll be there in early July (yes, peak season unfortunately).