Advice on itinerary please!

Hopefully you’ve checked with the car rental agency to confirm you can take a car rented in Croatia to Bosnia-Herzogovinia and Montenegro. They often will add a Cross-Border fee to the rental charges as a per-day surcharge or a per-country surcharge. Be ready for that and producing the rental and insurance paperwork each time you cross a border. You can check rental rates at Europcar.com and Rentalcars.com . Be ready for sticker shock as rates this summer are quite high. Plitvice Lakes to Mostar is a 4-hour drive and involves crossing an international border of unknown time duration. Are you sure you’ll be ready to cross another international border to enter Montenegro after resting up just one night in Mostar? I would consider 2 nights in Mostar. Also, note that the currency of Bosnia-Herzegovina is not the Euro, as it is in Croatia and Montenegro. It is called the “Convertible Mark.”

You might find the charming town of Perast more enjoyable than Kotor to overnight in. It’s smaller, more navigable with a car and it’s only 15 minutes away from Kotor- where so many of the cruise ships dock.
Yes- staying in Dubrovnik’s Old Town is worth it ( as is Split’s) Like living in a storybook.

will add that after checking the car rental sites Kenko listed, you might check with UniRent. I had a great experience with them last September. I rented in Dubrovnik and returned in Split, so the opposite oft your trip. On my reservation, I asked about driving to Mostar for an overnight and all the paperwork was ready. I did not go to Montenegro. I chose city centers for pick up and delivery. For Dubrovnik, this isn’t hard but I would be hesitant to head out of the city center in Split as a start to my driving experience. :)

I found Google times to be pretty good for estimating times. Border crossing times can vary. You just have to account for that possibility - and maybe research which ones are typically a little faster.

You are covering ground but for adults, it’s not too fast. As long as your kids are good car travelers, it should be ok.

Maybe Travelmom can provide the website for Unirent
because mine are showing the smallest car is going to cost $900 for five or six days before adding on insurance and cross border surcharges. Yikes!

Thanks for the replies! We have a car reserved and yes, it is unfortunately expensive, but have experienced similarly high prices here in the US lately so have made my peace with it. There is language around the extra fee for crossing into BH and Montenegro, so I assumed we would be able to pay for that on pickup, but perhaps I'll reach out in advance instead. Both pickup and drop off are at the airports--it was cheaper to reserve that way.

I was concerned that two nights in Mostar might be too much, and also wasn't sure where I would steal a night from. Would it be better to just do one night in Plitvice instead? My thought was to make a leisurely drive from Split, visit the Lakes the next day, along with checking out Rastoke/Slunj, then get up early the next morning for the long drive to Mostar. I'm not concerned much with the length of the drives--we are accustomed to it here in California--just the sitting in the car at the border will be challenging, I expect. I wondered if it would be wiser to cross the border near Plitvice/Bihac and drive through Bosnia to Mostar, but then it looks like the road itself will be much slower. Another option might be to leave Plitvice and stay overnight in Croatia somewhere near the border and go early in the morning to Mostar from a closer starting location?

Also, we are technically staying in Dobrota and not old town Kotor in an apartment close to the water, should we desire a swim. Would you recommend Perast over that?

Here’s how you can stay in Plitvice Lakes National Park one night and visit the park over two days. There are 3 hotels run by the government that are smack dab at the entrance to the park: The Hotel Plitvice, the Hotel Jezero and the Hotel Bellevue. If you stay overnight at one of these hotels, they will sell you a “One Day” ticket to the National Park. The “ One Day” ticket allows you admission on the afternoon you check-in to the hotel AND the next morning before you check out. During the summer the Park’s hours are 7:00- 20:00.
These are the optimal times to avoid the tour groups thronging the Park as they arrive, for the most part, mid-morning and depart mid-afternoon. The One Day ticket costs the same as one admission ticket but gives you two admissions to the park. And that’s probably what you had in mind by staying two nights.
The hotels offer free parking to their guests as well.
Have a great Trip!