Returning to work and bottlefeeding

My baby will be 5 months on Feb 6th and we exclusively breastfeed. I will be returning to work soon and have to make her bottles of my breastmilk. She's about 16 pounds. I read that 1.5-2 oz an hour that I'm away from her is enough. So if im away 8 hours, thats 16 oz total with paced feedings. Working Mamas, how do you make your bottles? How much milk (max) do i give each feeding? Is 5 oz in a bottle too much? I dont want to give her too much and stretch her stomach. Also, she doesn't really receive bottles during the day, We usually just give her a bottle at night, and thats no more than 2 oz to get her used to it. Thanks in advance!