It is a difficult situation. As far as going to bed later - I don't necessarily see anything wrong with that. If your husband gets home at 7-7:30 - he could be the one to do the nighttime routine - play for 15-20 minutes - get the PJ's on and put him to bed, etc and your son could still be in bed by 8:30. Of course he'll be awake for a little bit. My 2.5yo takes 30-45 minutes to fall asleep every night - no matter what. We lay her down around 8 also - sometimes later like 8:30 and she'll still be awake for 30-45 minutes.
But, he will fall into a different routine with his dad if you change it. Especially if he knows a little daddy time is built into his evening. It may take a few days, but if he knows that this is the new routine - he may start to fall asleep sooner and not get such a second wind and so wound up.
If dad can do things in the am - that's great instead - but it sounds like that door opening at night is at a bad time at night no matter what other time dad has had in the day!
I read the other responses too - even if he was up until 9:15 or so - whatever works in your family is what works. If he's still waking earlier - that would be the only problem, in my opinion and maybe the later bedtime isn't a good idea. Then again, in my opinion, it is ludicrous to put the TV on for a child to go to sleep too - but that's just me! I'm sure everything I do as a parent isn't seen as mother of the year for many parents!
It's funny you write about exercise - my husband and I just agreed to wake at 6 am every day and one of us would to the elliptical machine that we have and the other would workout in another way. We have just been sleeping later and later and it's awful! So - it's a little time together and to get the day started - we'll see how long it lasts! Ironically, it's not a New Year's Resolution either!
Good luck with your little one. Sometimes they just run the show and it sounds like he has other plans than going to sleep at 8 if that's when daddy comes home! LOL