Hey Jen
I started alternate milk with Grace at 11 mos for a different reason. Don't kick yourself over this, he'll do fine, and you're a great mom!
One thing I noticed with her is that it took a long time for her quantity of milk drinking to increase. I tried flavoring it and she would drink a little more, but it just took time. I increased her solids intake, as much as she would eat, and that helped. I also offered her water sippy between meals. Your care provider should be able to do those two things for you.
As for the nightwakings, I have to say for us, they were very similar with both kids at that age. The nightwakings increased a ton around the time they were almost walking, and again with Max because he teethed his four molars and two other teeth the same week he walked. :shock: You could try nursing in the evenings a couple times, and lots of cuddling if he wants, before bed, to help ease his need for you at night.
Now, your baby is pretty smart to understand that he can hold out and nurse at night. If you don't mind a night nursing or two while you transition into working and being gone from him (which is surely traumatic for him, so this would make it a little easier - for both of you) then by all means keep it up. I am a firm believer that they will stop waking when they are ready, and my ds just proved this to me about a month ago started sleeping through 12 hrs. He just nurses before bed.