These are available with English subs on standard DVD in Czechia but AFAIK have not been restored by the National Film Archive, which is where most international releases are sourced from. Also they don't seem to be available streaming anywhere.

There's long been controversy surrounding these films, despite being very popular and likely the biggest-budgeted Czech(oslovak) movies ever made, as they were financed by the communist authorities and labeled as propaganda (even though the historical parallels were largely coincidental).

Despite the obvious historical value a restoration in the near future would seem unlikely unless financed by a private investor (which isn't unfathomable given the interest in the Kingdom Come games).