In addition: The Foucault Reader has proved useful already:

p. 46:
But if we are not to settle for the affirmation or the empty
dream of freedom, it seems, to me that this historico-critical attitude [***]
must also be an experimental one . I mean that this work
done at the limits of ourselves must, on the one hand, open up
a realm of historical inquiry and, on the other, put itself to the
test of reality, of contemporary reality, both to grasp the points
where change is possible and desirable, and to determine the
precise form this change should take . This means that the historical
ontology of ourselves must turn away from all projects
that claim to be global or radical. In fact we know from experience
that the claim to escape from the system of contemporary
reality so as to produce the overall programs of another society,
of another way of thinking, another culture, another vision of
the world, has led only to the return of the most dangerous
traditions.

***
This entails an obvious consequence: that criticism is no longer going to be practiced in the search for formal structures with universal value, but rather as a historical investigation into the events that have led us to constitute ourselves and to recognize ourselves as subjects of what we are doing, thinking,
saying.

Hello - one of the classic resources on this is Johanna Oksala's aptly named Foucault on Freedom, which, if you're lucky, you might be able to find at your uni library or something similar. It's heavy on the phenomenology though, which you might find tough if you're unacquainted with it. There's also Charles Taylor's paper "Foucault on Freedom and Truth", which is one of the go-to papers on this topic, and which you can find online with a quick Google search. Joseph Rouse has a nice reply to Taylor in his article on Power/Knoweldge, which, while it doesn't deal with freedom directly, has things to say which are of direct relavence to your questions here. Also, you have have have to read Foucault's interview “The ethics of the concern of the self as a practice of freedom” collected in the edited collection “Ethics” (ed. Paul Rainbow). You can find it here. The distinction he makes between liberation and freedom is crucial.

My own approach to this question - it's one that's interested me for a long time - is shaped though psychoanalysis, which, although seeming somewhat tangental, has some of the best things - imo - to say about the way Foucault approaches freedom. In this vein, check out the first chapter of Joan Copjec's Read my Desire, the whole of Fabio Vighi's Zizek: Beyond Foucault, Aurelia Armstrong's article Beyond Resistance, and even Judith Butler's The Psychic Life of Power. A useful read might also be Wendy Brown's States of Injury, although that's a little bit more political theory based than 'philosophy proper' (but Brown is nonetheless among the best readers of Foucault on freedom, and has the merit of using and extending, rather than simply reiterating, Foucault's views). Not all of these approaches or authors agree with each other, but I think they're great reading to get a handle on this material.

Briefly though - no, there is no such thing - or rather than can be no such thing - as extra-discursive freedom for Foucault. Freedom is always imbricated with power and there is no freedom that can exist 'beyond' it.