Size is not the factor but skill of the surgeon and where your tumor sat, wrapped and where it pushed. So, some things may come back, but likely a few hormones may be lost forever.
I am Panhypopituitary not so much from from my pit surgery but my thyroid, adrenals, ovaries etc were all removed. Lost growth hormone as well and so the only thing I have is ADH. After surgery it takes a bit to get managed to normal and then settle. I still see my doc every 6 months for testing and I am 14 years out. MRIs become less often after 10.