first off, coaching critique, why are you running a championship event for the first time. usually i find these posts insecure -- you should have some clue from practice or a meet. but you haven't run it all year.
second, 800x2.25=5:23. (3200-35)/2=5:25. that's what some conversions say. but that's slower than you say you ran last year.
third, given the conversions are goofy here, surely you ran the mile some other year. surely you ran the 3200 that year. you ran the 3200 this year. how much have you improved in the 2 mile? that should vaguely hint where your mile might land. like if i have dropped 20s in the 2 mile this year, maybe i can drop 5-10s in the mile.
fourth, if you're asking for pace information, just find your usual crowd for XC or the 2 mile. you should know who in your area on the other teams you can go with, who barely beats you, who you barely beat. or if you have a teammate roughly your speed. start with the sensible neighbors and then make a move as the race progresses based on how strong you feel later on.