You can print A5 sizing using the A4 template, see instructions below. This is because A4/A5 are the same proportionate dimensions. But it won’t work the same way with Letter/Half Letter, because the dimensions aren’t proportionate. When Letter is printed ‘2 to a page’ you get two elongated halves.
If you want Half Letter, and are printing on Letter paper, the best workaround will be to open the A4 document (instead of the Letter size) and select ‘print 2 to a page’ in your print settings.
Printing A5 Instructions
1-For A4 Printer: Download the A4 planner from Google Drive
A5 is actually a perfectly scaled down version of A4, so you will need to download the A4 size in the Google drive folder first.
2-Select ‘2 to a page’ in your print settings
It will look like this (see image below) when printed. Then you can guillotine or cut down the centre to get your two A5 sheets.
*See step 3 if you have an A5 printer.
3-For A5 printer: use the A4 template
Open the A4 file and go to your print window > printer property settings. Select A5 in Printer Paper Size from drop down menu (eg. see yellow highlight in image below)