The download size of your Web-to-Print edited templates will match the specifications initially set up in the InDesign template.
You can select to download as either a PDF, JPEG, PNG or IDML file type.
If the templates includes multiple pages it will download as a single 'ZIP' file.
For PDFs, the preset used is High Quality Print if crop marks are enabled, and Digital Interactive if they are disabled. Custom PDF presets are currently not supported.
Once downloaded you can change the print size through your computer's print settings.
If you require an array of different sizes from your template, then different sized versions will need to be created in InDesign and imported into your platform.