I have the same issue. It is a pretty big keynote with 174 slides, and 2 hours of narration, recorded live.
I tried using small size video exporting settings but I got that error message of not enough space or a file error. I do not believe is a space problem beause I have 1 TB of free space on disk.
If somebody have an answer, I really appreciate any help I can get.
Thanks in advance.
I tried using the basic setting:
I tried on maximum quality, CD-ROM and web.... same issue.
Then I tried a Custom setting changing the frame rate to 15 fps, and I`m not sure if I check H.264 or I leave on Animation. Same problem.
Now I record it using quicktime and input the audio from a professional recorder I use on the event. I was able to record both the screen and the audio BUT now the audio is slower than the video and needs some editing (I will change the speed of the video part using final cut pro x).