Wouldn't one use two-photon microscopy? Patch clamp is quite limited in comparison.

There also is the combination of both methods - not surprisingly, they write how hard it is in a living brain (the clamping, the two-photon microscopy part is much easier): https://www.the-scientist.com/daily-news/robotic-patch-clamp...

Here is an article describing "three dimensional two-photon brain imaging in freely moving mice using a miniature fiber coupled microscope": https://www.nature.com/articles/s41598-018-26326-3 (the experiments that I was aware of all still were done on a sedated animal with a fixated head).