if youre dealing with lots of data
or csv to array
or json plugin (in progress but very useable)
or combination of these
the savedata can be alot smaller than the data you need to run your game, so i think webstorage should be ok
edit: to load the data you would just place the data (csv or json) in the files directory and use ajax to load the data, on data loaded you get the string in ajax.lastdata, and with this you can continue, .. dont know if the plugin deals with the loading.
you do have to be somewhat comfortable with c2, to use all of this, and large data games in general...