Looking around this morning this is quite interesting and can be done via firmware. If true than its pretty exciting to think when needed our A7II can pull off a 48mpx image. Now not sure you need a tripod or not but heck I have no issues using a tripod when doing landscape type work anyway when needing a high res file.
Thinking ahead does that make a A7rII a 50mpx cam when announced next month or so. Check this out as it's pretty exciting
Sony Rumors « NEW CAMERA