Pumping Question..

I work 8 hour overnight shifts. my baby is 2 months old & he only eats one time while I'm at work around 9-10 then I feed him as soon as I get home at 3am. should I only pump once while at work? pumping once ill get 5 oz, which is enough for the next night.. pumping twice I get anywhere from 10-12 oz. I already have a small stash in my freezer with about 80oz. the reason I ask is because since my son is on a schedule, if I wasn't working.. I wouldn't be feeding him until 3am anyways because he sleeps 5-6 hours through the night. what does everyone recommend?