How complicated is carpal tunnel surgery, ganglion cyst, and trigger finger..all at one time?

Not too: In good hands that surgery is not too complicated provided it's not on both hands.

More than one at tim: But there is no set "how" or amount. It is a great subject to talk about INDIVIDALLY with a surgeon if that is what someone is seeking. Much depends upon how severe each problem is by itself, how healthy the person is, age general health, risks vs benfits of doing it all at once vs having more than one trip to the OR. Where the ganglion is ie the finger near the trigger or somewhere else.