Wow hugh and blondes, your pretty well established on 3 meals! 
DS has been better but just finishing one cube if that. I stopped for a couple of days during milk changeover. The sleep lady recommended thickening his feeds and making porridge with arrowroot (can also mix a veg into this) so I tried that yesterday and it seemed to work well.
She suggested we stopped the df whilst we are having the multiple night wake ups until the new milk kicks in so last couple days he has been going to sleep at 7pm and up for feed at 2am-ish. Having 5 feeds in total of 6oz each. He's finishing these mostly but i purposely kept it at 6oz during the changeover.
Carol I read somewhere that to sleep through the night, they need to be having around 32oz I think it was. It was definitely over 30oz but maybe not quite as much as 35oz. Hope you have some success with getting more feeds in during the day. If she is teething it's probably a little sore for her to drink so perhaps move up teat size to ease the pressure on gums or try something like anbesol before feeds?