Looking for some input on scheduling my final 6 weeks into IMWI

Wow.  You've got it jammed in tight!

I'm a big fan of long bricks for first timers to check pacing and nutrition, but I've never done it with an over distance ride.  I have found that the ride needs to be more than 90 miles and the run 6-9 miles. Also, I don't see any advantage to doing an 18 mile run immediately after a long brick. 

So, here is what I would suggest:

18 miler Aug 4th

100/6 brick Aug 17th.  Remember to run/ride at IM pace.

Swim on Aug 18th to loosen everything up.

50-75 mile ride Aug 25th

btw, I would ditch the Rev3 Dells, but I see it's right in your backyard.  If you don't really want to do this race I would skip it, train regular, and get some rest. 

I completely agree!  This looks a lot like my August plan.   I would ditch Rev 3 for this year and maybe do the Racine HIM or Door Co (depending on where you live) 

Racine / DoorC are in mid July.  They'll give you a good idea on your race fitness and let you perfect your nutrition plan (for 2x the distance).  

Others might disagree with me, but I don't really see the benefit of a 120-130 mile ride in August.  I'd (at some point) ride the entire course (stick & loops), then maybe transition and do a 3-4 mile run.

Yup Racine is most likely out the window for me. Raced the past couple of years and doesn't offer much that I want. I am planning on DC in July, but dependent on the weekends of the races I may do Chisago. The more and more I think about it Rev 3 might not work out, or instead I will use that as a final tuneup and move my higher volume weeks to before Rev 3. It was not until after I signed up for IMWI that these commitments became true, so I am having a harder time letting go of ideas that I started to come up with this summer. 

As for the reason for the long rides, well 135 might be pushing it but I ilke the idea of 125 miles. First the body learns to become more and more efficient the further you go, and secondly by riding 15-20 miles further I am simulating another hour of work that will be done in the race at around the same HR. However, by riding and not running that hour, my body is not being taxed nearly as hard, and running off the bike 3-4 miles will better simulate how I feel from miles 10-14ish with that added hour on the bike. 

With all this said I may just ditch the long runs the day after, and follow suit with the rest of my training plan and do all of my long runs in the middle of the week on fresher legs with more recovery built in.

Again this is all rough draft material for me, but I did do over-distance riding for 2 HIM this year, and I felt a world better coming into T2 then I have ever before. With IMWI next year I am not training to finish, but put myself into a more competitive finish time (hopefully) and so the direction and focus of my training I believe should reflect that.