You can find detailed spec sheets for all of Toto's toilets here.
Looking at the spec sheet for the Dartmouth, it looks like the relevant measurements are not supplied.
In looking at our newly installed Toto Ultramax 854114SG, the floor bolts are exactly 12" from the baseboard, and I measure that the back-most part of the base is 1-1/2" from the baseboard. It's really hard for me to tell whether the back of the tank gets closer to the wall than this.
Hope this helps a bit.