Canva 300 pages pdf limit

So Canva has a 300-page PDF limit, could I create two PDFs both with 300 pages, and then somehow merge them to be one PDF, or is it too big for those online services to merge something that has 600+ pages?

The Acrobat Merge PDFs tool lets you create a merged, single PDF document of up to 1,500 pages. You can combine up to 100 files, with each individual file limited to 500 pages.

For FREE.

https://www.adobe.com/acrobat/online/merge-pdf.html