Thank you for all the replies. A lot of good nuggets of advice and some common themes here.
I’m about 14 weeks out now, so I think the most reasonable approach is to change up my training structure to 2 big workouts a week. I will do a threshold workout with 6-8 plus miles of work along with a long run with MP/slighter faster than MP efforts mixed in. I’ll incorporate strides after my easy runs to keep some leg turnover stimulus. I also think I will scale back my time expectations and target a 2:55 for this upcoming marathon and try to race a half and possibly some shorter races in the lead up. As noted, my HM time was relatively weak but I only raced one and it was in hot conditions (in August) and on a somewhat hilly course. My guess is I could have been 60 to 90 secs faster in ideal conditions but who knows.
Then after this marathon I’m going to take some time to race more shorter distances and really work on my 5k/10k speed before jumping into another marathon. Hopefully that will do the trick and thanks again for all the perspectives.