Best way to travel between Prague and Cesky Krumlov

Terezin and Cesky Krumlov are in opposite directions from Prague. If you rent a car, you'd be looping around to the north, then to the south of Prague for Cesky Krumlov and back. I haven't been to Terezin, but I assume public transit is easy. I believe there is reliable, direct train and bus service between Prague and Cesky Krumlov (there was last time I checked).

I had a car when I was in Cesky Krumlov. Driving in Czech Republic is pretty easy. FYI, there are some other neat small towns in that region (that may be a lot less touristy than Cesky Krumlov). Jindrichuv Hradec, Trebon, and Pisek are nice little towns.

Also haven’t been to Terezin, and last time in Prague and Cesky Krumlov was a long, long time ago, but even then, train from C. Krumlov to Prague was easy. Not fast, but easy. Nowadays maybe it’s even fast. Trains work there!

...planning an overnight trip to Cesky Krumlov. How would you suggest we travel?

I followed the advice from the Main in Seat 61 and took the train from Prague to CK (I was not returning to Prague.)
https://www.seat61.com/places-of-interest/day-trip-to-cesky-krumlov.htm

You can buy your tickets online and he gives all the details. If you want to display your ticket on your phone, then create a login first on www.cd.cz and purchase your ticket while logged in to your new account. Then download the app on your phone and log into your account to view your ticket and display it to the ticket checker.

When I traveled, last fall, they were running buses for the 2nd leg of the journey. If it's train all the way, that will be even easier.

We are also interested in visiting Terezin …. Any input on this itinerary (destinations/tour groups/restaurants) would be greatly appreciated

I will be returning to Prague this fall and am scheduled to take the Terezin tour with Pavel Batel, highly spoken of on this forum.

Here is a recent forum thread with recommendations for his Terezin tour as well as Wittman Tours.

We took the CK Shuttle from Prague to Cesky Krumlov and also from Cesky Krumlov to Vienna. We chose the door to door option for both trips. I highly recommend it.

https://www.ckshuttle.cz/bus-cesky-krumlov-transfer/

For those who have taken the train between Prague and Cesky Krumlov, do they have toilets on the train?

Every train has a toilet.

Just yesterday we took the Regiojet bus from Prague to Cesky Krumlov for around $9/ticket one way. Worked great, made two brief stops and took about 2:50 travel time. Made reservation online the day before and was able to select adjacent seats. Was able to get the time we wanted but will book earlier next time as some buses fill up. Have fun!

I would second the suggestion to take the CK Shuttle. We just used this service (shared ride). It accommodates 8. The driver took us door to door from Vienna to Cesky Krumlov and Cesky Krumlov to Czechia. The scenery was beautiful, the van was comfortable, the drivers were right on time & courteous. Great customer service. We would certainly use their service again!

We are going to Terezin tomorrow with Pavel Patel. Highly recommended by relatives & friends who took this small group tour. If you are interested in a tour of the Prague Jewish Quarter we did this tour today with Pavel's colleague Yvonne. She was AMAZING! Knowledgeable, compassionate and kind. She is the best. www.jewish-quarter-tour.com

Flixbus runs frequently on this route and stops closer to the center of CK than the train station, whether they go to the Spicak stop or the bus station (end point mentioned on schedules).