Backport of !513
I believe !513 (merged) should be applied to 1.1.x (and 1.0.x likely as well) because I replicated the issue & demonstrated this patch fixes it by adding an equivalent patch to the Ubuntu package source for version 1.1.2-3ubuntu1 (which is current on Ubuntu's LTS).
Summary for release notes
Fixes width of page created by File > New From Template > Blank Page...'s US Letter option
Checklist
-
Add unit tests (if applicable) -
Changes to inkex/
are well documented -
Clean merge request history