I know that after today’s solemnity we are celebrating “Ordinary Time”, but is there any provision for celebrating an “Octave” of the Assumption in some sense? It would seem that the placement of the feast of the Queenship of Mary exactly one week after the feast of the Assumption is a remnant of an Octave.
Even though no Octave is celebrated, there is no reason why you cannot personally celebrate one yourself with prayers of your choosing.
Not really. Although the feast of the Assumption had an octave until, I think, 1955, the feast of the Queenship was not on the old calendar. The Octave of the Assumption ended with the vigil of St. Bartholomew on the 23 of August.
Source: 1934 Antiphonale Monasticum (monastic antiphonary)
There were a lot of changes back then. The celebration of the Immaculate Heart of Mary was created by Pope Pius XII on August 22 in 1944 and then the celebration of the Queenship of Mary was also created by him on 11 October 1954. Queenship of Mary was originally celebrated on May 31. Pope Paul VI moved both in 1969 to their current positions. May 31 is now the feast of The Visitation of the Blessed Virgin Mary, also moved by Pope Paul VI in 1969.
*]Immaculate Heart of Mary memorial: August 22 -> Saturday after the Solemnity of the Sacred Heart of Jesus (Friday)
*]Queenship of Mary memorial: May 31 -> August 22
*]Visitation of the Blessed Virgin Mary feast: July 2 -> May 31
Interestingly, in the Byzantine Catholic Church, the Dormition is on August 15 and the leave-taking of the Dormition is eight days later (and he pre-fest is one day before), so each of the following days (and the day before) also includes some prayers proper to the Dormition.