My DS wakes 45 minutes into his nighttime sleep too. Hmmm. Isn't that interesting? Some nights he falls back to sleep on his own; sometimes he needs my intervention. We cosleep, too, so I'm usually right there.
DS goes to bed between 7 and 7:30 pm, but we're on the road in the morning by 6 am - our day starts early. I wonder if you got DS up earlier, that over time, he'd gradually want to go to sleep earlier. It's hard, I know. My sister's kids stay up late, because they don't all get home from work/daycare until about 5:30 in the evening (whereas, we're all home by 4:00). After dinner, clean up, baths, a little relaxation, three hours have passed. She sticks to a late bedtime, because otherwise she'd have so little time with them.
Our challenge, despite DS's early bed time is allowing me to get out of bed and go spend time with DH or clean or whatever. If - I mean, WHEN - DS wakes up after that 45 minute mark, and I have to run upstairs to settle him back to sleep, it takes a lot longer than if I'm right there next to him. So... unless I have urgent things to do downstairs, (sigh) I crawl in bed at 7:00 too, and do work on the laptop or DH and I watch a movie on the laptop or read. I long for the freedom to just go sit in another room and do my own thing - but it's gotten so that if I do, I have a hard time relaxing. I'm kinda always on edge, ready to bolt if DS wakes up. He's AP-trained me well.
Good luck with your transition. You might also have luck making the change now, when evenings are still dark. Just some thoughts...
DS goes to bed between 7 and 7:30 pm, but we're on the road in the morning by 6 am - our day starts early. I wonder if you got DS up earlier, that over time, he'd gradually want to go to sleep earlier. It's hard, I know. My sister's kids stay up late, because they don't all get home from work/daycare until about 5:30 in the evening (whereas, we're all home by 4:00). After dinner, clean up, baths, a little relaxation, three hours have passed. She sticks to a late bedtime, because otherwise she'd have so little time with them.
Our challenge, despite DS's early bed time is allowing me to get out of bed and go spend time with DH or clean or whatever. If - I mean, WHEN - DS wakes up after that 45 minute mark, and I have to run upstairs to settle him back to sleep, it takes a lot longer than if I'm right there next to him. So... unless I have urgent things to do downstairs, (sigh) I crawl in bed at 7:00 too, and do work on the laptop or DH and I watch a movie on the laptop or read. I long for the freedom to just go sit in another room and do my own thing - but it's gotten so that if I do, I have a hard time relaxing. I'm kinda always on edge, ready to bolt if DS wakes up. He's AP-trained me well.

Good luck with your transition. You might also have luck making the change now, when evenings are still dark. Just some thoughts...