reducing size of gallery backup file when transferring

Gallery version:1.5

I'm trying to move my gallery to a new host. I read the information here: http://codex.gallery2.org/index.php/Gallery1:Migrating_Gallery which is very useful, but my problem is that my gallery is 2GB of data. When I try to upload this file to my new host the transfer times out. I could use split and cat to break the file into smaller pieces and then join them back together on the host, but I'd rather cut down on the size over all.

I think that if I remove the thumbnails and the medium sized photos I would save a lot of space. I'm thinking of removing all of the ".sized.jpg" and ".thumb.jpg" files from the directory with something like find ./ -name '.sized.jpg' -exec 'rm {};' but I'm curious if I do that will Gallery recreate the thumbnail and sized images or do I need to change some settings before I do this?

Thanks!
Greg