Hi,
unfortunately there is not a real way to cancel the updates once they started...
There are some things I could suggest that could help here...
A) If you are installing a lot of feature updates (named something like 1904 or 21H2) these can be skipped by doing an upgrade via the media creation tool. Then you just need to do that, and then install the commultative updates.
B) You could use remote access (such as remote desktop) to access the device from your phone or another PC.
C) Check these registry keys in case this is an option for you (don't think it's worth the effort though, and you only get another 15min from what I got by quickly reading over it.)
Other than that, you can schedule a restart command from the command line, but you would need to know exactly how long the update is going to take (which is most likely not the case)
However, at max it should be about 3-4 restarts, so at this point, it's probably about to be done...
Sincerely,
LightJack