well, i cant speak for your T1. i dont know what kind of pizza he likes. different pizza places, and i’ve said this before, have different formulas for making their pies. i have only gone to one place for my pizza; i figure i will go to my most favorite place and return and return and return so that i can figure out a guesstimate for that particular recipe.
some places use extra cheese, some have more sugar in the sauce, some are more thick crusted, etc etc. i recommend taking an educated guess based upon how he digests other similar foods with high fat content and simple carbs. i started basing my experiment on how much i needed for a grilled cheese sandwich, and then i went from there. i missed the mark so many times before i had some success with it.
also, i dont know what your target range is, so i cant help you there. i like to be between 75 and 110. if i am over 140, i consider that high. (it used to be 80 - 180 BG as my target range)
i will say a prayer if you say one for me . i wish you all the very best. let us know how it goes. i know everyone here (pizza junkies) will benefit from your experience.