Initially, when making a page responsive I would make a new blank page, work on it, and when it was finished, rename the original to 'original-o', then rename the new page to 'original'. (Whilst working I would copy any wanted elements from 'original' onto the new page.)
Unfortunately, when renaming the original page, it changed its entry in Navigation Menus to 'original-o' and I had to go through all the menus to change it back to 'original' after I had renamed my new page. If I had a Master page containing the Navigation Menu, that would have been a simple job, but with Responsive pages using Layout Grids, it meant I had to make the change on each page.
To avoid these repeated changes, I realised that I could do the following:
Clone 'original', and rename it 'original-o'
Removed ALL the elements from 'original' (using Ctrl-a and Delete - but checking in the Object Manager for any strays)
Work on the 'original' page, copying any wanted elements from 'original-o' onto this page.
Thus the Navigation Menu entries would be unaffected (and the entries under page properties retained).
As stated, this may be how most people work anyway, but for 'thickos' like me it may be of some help.
