does it come down much if you compress it with something like winzip - would really like a copy of this one if possible.
i believe you can probably only do what you are saying with uncompressed video, or video in an intermediary editing file format, and you still cannot do that with a zip compressor even then.
generally i believe video does not respond at all to zip or the other standard dictionary-based compressors. a video can obviously be reencoded to another format using a different video compressor which can reduce file size, but a lossless re-encode/recompression intended to reduce file size is not really an option with these h264 or other keyframe-based formats that are not intended to be edited further. Usually such attempts may reduce the file size, but will also make the resolution and quality significantly worse.
Also, the fact that most vlogs are recorded on consumer webcams, even if in HD, already outputs a compressed, keyframe-based, inflexible format from the get go! Also, YouTube will also automatically re-encode it for sure into this inflexible format (usually with at least a slight loss in quality from the original) no matter what.
so in a nutshell, i think "no" would be the answer for zip compression of videos to reduce file size. great question though!