Published Course Size issues

I'm getting ready to do QA on my first Captivate course, which is designed to be responsive. Normally, I do my first QA offline from the LMS by publishing the file to Dropbox and sending the clients the index.html link.

However, when I test the link on my iPad and iPhone, the loading icon spins for a bit and then the mobile browser eventually crashes (it plays fine on my laptop). Earlier versions worked (and still work) this way. The only difference I can think of is that the published files are about 20mb on my latest version. Could that be why it's crashing on mobile? I'm not sure how to reduce the file size more than just a bit, as it's a big branching course with over 80 slides. There's a little video as well.

If the problem is with Dropbox, does anyone have a suggestion for a better way to send the course outside of the LMS? I may try my personal webserver.

Thanks in advance.