Hopping in here, as i was going to start a similar thread. My dd is almost 8 w and will take only between 15-18oz/day. we still have some feeds with just 1oz most are 2 and some are 3oz (also formula fed) I have been logging for 5 days. The kicked is that she has slowed down how much she eats. She can go longer than 3 h without feeding, she sleeps very well and isn't showing any signs of lethargy. She has at least 1 poop and her diapers are wet. She has gained weight, I can tell by looking.
But, the thing that is killing me is that she was up to mostly 3-4 oz bottles and now she is back down to 2oz/feed. Its pretty stressful, but I guess hearing that others have the same issue helps. Maybe she is just a small eater. but like one of the pp my son inhaled 8oz bottles and never stopped even when he switched to milk he was drinking 32-40 oz/day along with large solids appetite.