After the death of Józef Montwiłł, his nephew Władysław Montwiłł inherited Mitėniškiai Manor in 1911.
After the Soviet Union occupied Lithuania, the manor was nationalized. Understanding the danger that had arisen and seeking to avoid repression, W. Montwiłł and his wife Maria Montwiłł and her mother, Ludwika Kończa attempted to cross the USSR-German border illegally and seek refuge. However, their escape attempt did not succeed. On 1 August 1940 the family was arrested outside Kybartai by border guards of the People’s Commissariat for Internal Affairs of the USSR (NKVD). They were prosecuted for their attempt to cross the state border of the USSR illegally.
According to the 26 April 1941 protocol of the Special Deliberation of the USSR People’s Commissariat for Internal Affairs, W. Montwiłł, M. Montwiłł and L. Kończa were sentenced to three years’ loss of liberty in a labour correction camp. W. Montwiłł died in the camp in 1942. M. Montwiłł managed to escape from prison and return to the family’s Mitėniškiai Manor, where she lived until the end of World War Two. As the Red Army encroached on Lithuania, she fled westwards and later left for the USA. She died in 2002.