In my post I said that I've never seen my SOC drop below 85% for my 180AH bank. On a typical day during my 7 weeks of cruising this summer it never fell below 93%. That is a generous amount of excess capacity, do you really think that I would benefit from carrying even more batteries? What would I gain at that point besides more dead weight on the boat?
I usually feel like I could have saved weight and money by going with a single group 27 or 31 battery instead of my pair of group 24 batteries.
I did measure all of my loads beforehand. That was my suggestion to the original poster: calculate loads, figure out your daily consumption, and plan accordingly.
40ah per day is 480 watt hours. That is extreme considering that your average modern laptop (such as the Lenovo Yoga 13 or Macbook Air 13) has a 60 watt hour battery and can run for 7-10 hours on it. Tablets have even smaller batteries. 480 watt hours should allow for 4 current laptops to be used 24x7.
Older laptops did use much more power than modern ones (Intel Haswell chips use a fraction of the power of their predecessors). It might be worth upgrading.
In your case your system seems well sized and 180Ah with LED and no DC fridge is not bad on a 28 footer. If you never dip below 80% SOC then your bank will last a long while, expect 8+ years. What do you use to monitor SOC?
As for the op with refrigeration and a 34 footer 375Ah is pretty typical size wise and I would not consider it overkill if you want the entertainment items and a few days of peace & quiet.
My customer with the 40Ah/day habit does have an older 17" laptop for nav (old blue & silver HP) his wife has a laptop and he also has his work laptop. None of them are low consumers. I have measured his nav computer peaking at 7.2A while processing & charging and this was running off 12V.. They also run a Wilson cell booster because the are both physicians and often need to be within cell range. He also has two kids with an iPad each, plus phones and more gadgets like kids video game stuff, GoPro, multiple cameras etc. constantly sucking on the system.
I have a customer with a very similar system to yours minus the solar. 2 G24 house, all LED, no fridge and a stock 55A alt. He bounces between 50 & 85% SOC when out cruising and I suspect most of it is computers and his auto pilot because his e7D and instruments etc only burn under 3A unless radar is spinning. He does run multiple cabin fans though... His batt mon is manually reset when he leaves the dock to keep it from drift issues..
Before we had kids and LiFePO4 we could survive comfortably on 25-30 Ah / day now we are around 50Ah - 75Ah. We could use less but we don't want to hear the engine so use DC refrigeration more than the engine driven like we used to. In the off season with the Espar that bumps closer to 85-90Ah..
Shallow cycles like you are doing will lead to much longer battery life but every boater has different needs and I find a large percentage are more often undersized for their loads.