6 week old sleep advice

Ar

My son is 6.5 weeks old and has been the best night time sleeper. He usually sleeps from 9:00/9:30-3:00/4:00, eats, and then sleeps again until 6:00/7:00. After the second time he wakes up, I try to get him to go back down, but lately, he only wants to sleep that last hour or two with me. I am going back to work in 3 weeks and want to slowly start the process of shifting his bedtime earlier to 7:00pm because I will have to get him up at 6:00am once I go back.

As of right now, I usually try to put him down for one more stretch of sleep after the second feeding, but now that he is sleeping for such long periods of time, he is restless when I try to put him back down after the second feed. He is sleepy, but the second I put him down, he jerks around in his swaddle and starts to cry and wake up. For the last 3 weeks, that’s when I pick him up and take him into the bed with me for another hour or two because he refuses to sleep on his own at that point. I don’t like cosleeping because it scares me but he won’t sleep on his own after that point.

My question is this: should I just let him wake up after that second feed and just try to get him to have another nap during the day? That would only give him about 8-9 hours of sleep at night once you take out the feeding. It’s about an hour less sleep than I had planned for when I go back to work but it seems like he might prefer to sleep in two large chunks. If so, should I just plan on putting him to bed at 8:00 instead of 7? He’s six weeks so i know his sleep will change many times but I’m trying to plan ahead in hopes to give him the best sleep possible when I go back to work so he’s not miserable.