Angel,
If your tiddlywiki is inside an app such as quine it only accesses the local file, no data needed. Then the trick is to sync it at home (not sure for Quine)
If a single file wiki is already loaded in the mobile browser and you turn off auto-save, it will stay in the browser until you close the tab, you could protect yourself further by having the local storage plugin active and saving any changed tiddler. This will need a manual save once you return to your wifi and can still save to tiddlydrive then when you are on cheep data. The local storage has some caveats for its use, such as don't use it on a low memory remaining device and the browser may purge the local storage.
There are so many ways to achieve what you ask, it is a matter of rounding down the options and asking for help here.
Regards
Tony