Raw video has a much, much larger file size (many times larger) than a compressed format. In iMovie, you get a compressed format by using the "share" function to export it to a smaller size.
If you still have your edited video, you could go to Share -> Export Movie... and select one of the sizes listed there (Medium 640 x 480, Large 720 x 540, etc.). Depending on the format of the video you took, you might see different values (i.e. if it's in letterbox proportion). You would then give the file a name (it would most likely have the .mp4 extension already defaulted for you) and save it on your hard drive somewhere, like in the Movies folder.
Once it's done exporting, which could take up to 20-30 minutes depending on how long the movie is, you would then upload that exported file to Vimeo. That also might take some time, but it would be far less than uploading the raw video.
If the upload is still going to take 7 hours or whatever, I'd recommend going to someone's office or a library or a cafe to try uploading it where there's a more robust connection. If you're not on a laptop, you should be able to store the movie on a USB stick or DVD and then bring that to the library or something.
Sorry if this is throwing a lot at you. I hope it helps.
Jeff