I don't think rendering the page on the webserver is going to appreciably reduce its size.  The page renders fine on mobile atm too (aside from the fact that it hasn't been made fully responsive).

The only concern with rendering in the client vs server would be whether or not the client had a CPU to support all the redraws, but that's related to how the page functions, not loads (and I don't think would be a big issue with today's smartphones... some older gingerbread Android devices might have some problems).