Bogertophis is the Trans-Pecos expert. However, my two cents is it probably won't hurt to feed an adult mouse every two weeks (assuming he can handle an adult mouse - is he over 250G +/-?)
Figment, one of my corns got a little chubby on weekly feedings and I moved him to every 2 weeks and he is doing great and has leaned out.
Solana, my female corn, is a little smaller at about 360G and happily eats every two weeks as well and has great body condition.