Should be rated as "no big problem" times, as I mentioned, there are no trucks allowed on the Autobahn during the weekends.
True, but the OP' plan leave Frankfurt Saturday afternoon and leave Prague at 0600 on Sunday morning. What would be the point? Get to hotel at 2030, have a quick bite to eat, have an early night, get up at the crack of dawn, drive back.
Definitely not my idea of fun! In fact I probably wouldn't even do the trip by air.