If you don't want to change the scale factor, then, the steps would be
1.) Select all
2.) Group
3.) Format > Protection --> protect aspect ratio
4.) Change Page size
5.) menu bar > View > Size and Position window
6.) With the group selected, change either the width or length, e.g., width
was 12 in, becomes 12*0.707 in. Ungroup.
Either technique will work, depends upon what you need the scale factors to
do.
HTH
Wapperdude