If I already own a physical copy of TOTK with 1.1.2 installed and go out and buy another copy, will that copy automatically use my save data from the 1.1.2 cartridge, or will it start on 1.0.0?

This is actually a very interesting find. With the current rules this is "technically" a viable strat because the rules do not clarify whether or not a hard reset must be preformed prior to the run. Now realistically there's no way the moderators would allow this as it would render all previous Any% strats/runs irrelevant, but I do think this warrants clarification from the rules.