Yes, even with a long 2hr nap in the afternoon , he would be overtired because he is awake for such a long time in the morning. I would honestly bring the nap back & put him to bed early until he adjusts. The overtiredness might catch up (cause it can be cumulative) & he might be resisting naps as well.
& no, I don't think you should start feeding him now. Its going to become a prop & then you'll haveto deal with something new when you get back home. He's going to keep on waking up for that bottle.... so if it were me... I wouldn't. He's not waking up because he is hungry (providing he is eating well during the day)... he is wakign up becuase of the recent changes.