PDF itself has one architectural limit: Because ten digits are allocated to byte off-sets, the size of a file is limited to 1010 bytes (approximately 10 gigabytes).
and
The minimum allowed page size is 3 by 3 units in default user space; the maximum is 14,400 by 14,400 units. […] Beginning with PDF 1.6, the size of the unit may be set on a page-by-page basis; the default remains at 1/72 inch. (See implementation note 177 in Appendix H.)
That implementation note, by the way, roughly states that “the UserUnit entry of the page dictionary” is more or less a dimension multiplier, and that:
Acrobat 7.0 supports a maximum UserUnit value of 75,000, which gives a maximum page dimension of 15,000,000 inches (14,400 * 75,000 * 1 ⁄ 72).
and
The magnification factor of a view is constrained to be between approximately 8 percent and 6400 percent. These limits are not fixed; they vary with the size of the page being displayed, as well as with the size of the pages previously viewed within the file.
All in all, dealing with a page of such humongous dimensions sounds rather bothersome.
From the reference document:
“Implementation limits”, p. 991ff:
and
That implementation note, by the way, roughly states that “the UserUnit entry of the page dictionary” is more or less a dimension multiplier, and that:
and
All in all, dealing with a page of such humongous dimensions sounds rather bothersome.