I’m building such a beast right now.
Go bigger. Big Apple Lite, 2.35″ Get the full benefit of fat wheels.
I have dicked around with this for years trying to get an effective fatter tyre in a road bike. Last year I built up one of my odd bikes and put BAs on it. I was amazed at how free rolling it was, especially on the less than perfect surfaces of most roads up here.
Then I spent a winter on my fatbike which has shown me the benefits of fat wheels – my 29er remains unridden since the ‘Puffer.
So I have taken a spare 29er frame I had bought for a belt drive experiment and built it for road use. At the rolling chassis stage right now, with a bit of luck, running by tomorrow.
Using a 29er frame, I have the option of dropping a tyre size if I end up not liking the BAs for general use.