As no one has replied... Why don't you get a page set up as you want and save it. If you are going to use this same setup several times to avoid the software reverting to the default, save it say 20 times as a blank page. Then you can copy your 'over-wide pages' to one of these. Then as you use up your 'bank' of blanks replace then.
This is probably the long way round, but at least you'll go back to the top and someone else
may well have the answer.