Like @CCarreiras has stated make all the sheet sizes in one template.
If you want some ilogic knowledge type Ilogic drawing automation into the internet explorer and you should get lots of hits relating to this forum and to other companies who kindly share sample rules. A internet search of ilogic drawing sheet size change will get you lots of examples.
Here is a somewhat advance rule.
https://microconcepts.typepad.com/design_automation/2015/09/change-sheet-size-update-title-block-and...
The other method is to jump into the ilogic rule editor, find drawing in the category browser and pull out the relevant snippets. I would suggest an external rule as you will likely want to modify the code externally to the drawing.
In addition you will need a parameter sheet size in the drawing to change sheet size. Then I would suggest you create an external form and drag the sheet size parameter into the form.
If this solved a problem, please click (accept) as solution.
Or if this helped you, please, click (like)
Regards
Alan