I have a large vector image I've drawn in adobe illustrator that at some point needs to be printed on a separate machine without access to illustrator. If I shrink the image to decrease file size for upload then export the image as a PDF can it be scaled at the receiving end again via printer settings and still maintain quality if enlarged?
Illustrator exports vectors inside a PDF as vector, unless you rasterized them first. Vector files are infinitely rescalable, either in print, or when viewing on screen with suitable image viewing software.
Shrinking a vector image's physical size will not reduce the file size of the image.
If there was a printer big enough, you could print a vector image the size of the Empire State Building, and it would still look tack sharp. Vectors do not contain pixels, therefore there is no degradation when making them larger.