Like this. I actually researched the question (asked Doug Smythe, who RENDERED the T-1000) and posted this amidst a sea of guesses and bizarre replies answering questions that weren't asked.
https://www.reddit.com/r/vfx/comments/1b6snjd/when_t2_was_made_in_1991_what_resolution_were_the/
@owenhammer yup
We did MI3 at a resolution only slightly higher than that
@tvaziri Just to clarify, this pioneering visual effects film did the work at 1728x720 even though the standard of 2048x1556 had been established, and the Super35 format gave them even *more* resolution since they didn't have to lose the soundtrack area.
If it was 1728x1456, anamorphic, that would make sense since it is the standard 1828x1556 minus 50 pixels on each side for overscan.