Questions for: whole grain miche, 1800 g and up.

My next goal is to bake a 4 pound (1.8 kg) 100% whole wheat boule/miche.  Why?  I just like the way they look.  (And to impress friends of course.) Due to size, this will have to be on my 14.6" baking stone or Lodge 14" cast iron pizza pan, not in a dutch oven.

Forkish talks about this size, and bigger, in FWSY, but he goes up to only 30% whole wheat.  His 1.8 kg boule, Country Blonde (10% whole grain), or Country Brown (30% whole grain) is on page 172.  He bakes at 500 F for 5 minutes, then at 475 F for 30 to 40 minutes, then "a few minutes" with oven off and door ajar.

Reinhart covers the topic, but with only 85% extraction flour,  and only up to 1355 g weight.  Or, 100% WW, but much smaller loaves.

Reinhart's high extraction flour miche, 1355 g, is on pages 164-168 of Whole Grain Breads, where he bakes at 425 F for 50 to 65 minutes, steaming with 1 cup of water.

This web page http://www.wildyeastblog.com/high-extraction-miche/  bakes 1800 g of high extraction flour dough at 425 F for 45 minutes (first 10 minutes are with steam), then another 15 minutes with oven turned off and door ajar.

Questions: 

Has anyone here baked 1800 g, and larger, boules/miches of near 100% whole wheat?  Is it doable, that big and nearly all whole grain?   Or am I setting my goal too high?

If so, what oven temps and baking times do you use?   So far, I've learned that the higher percentages of whole wheat, along with the corresponding/requisite higher hydration, require longer bakes at lower temps.  

I don't have a large roaster pan to cover the boule/miche on the stone, but could buy one.

I do have pans that can be used for steaming the oven, and have done that in the past.