I would recommend you build the game and if you did, maybe separate the game and the source, maybe that would fix the storage problem.  

Hey, I don’t got Unity installed on my system (promise I’m not crazy, I use either Phaser or Godot) so I don’t think I’ll play your game in this format. If you get the build to work and upload the executable, I’m pretty much up for it! Maybe ask the jam community for assistance?

Are you sure your game has to be over 700MB? You might find some files you can delete, me and probably many others are not willing to download such a game file, especially when there is no additional information attached. Try adding a description and some images :)