I noticed already have a release \"addHTML() can now split the canvas into multiple pages\" which can find through this link : https://github.com/MrRio/jsPDF/releases/tag/v1
With using pagesplit: true it always stretches the pdf output.
Try to use an old version of jsPDF with html2canvas of course.
Sharing the result of my 2 days trial to achieve the multipage PDF generation with addHTML not fromHTML since it looses the CSS rules.
then the PDF should be just fine as follows:
Hope this would help. Thanks!