Major Problem: 135mm rear spacing road touring frame with shimano 5800 11 speed cassette? I have a brand new traitor wander touring frame, it has 135mm rear spacing like a mountain bike (this is a road touring frame).  I bought 29er mountain bike disc wheels that were advertised as 11 speed.  After I tried building it up I realized that my brand new shimano 5800 11 speed cassette will not fit - the freehub is too narrow to accept the 11 speed road cassette.  The problem is I have these wheels and this new full 105 drivetrain.  what will be the cheapest way to make this work?  What shimano disc hub will fit a shimano ROAD 11 speed AND be 135mm wide AND be 32 hole?  Am i screwed?  I could just buy a new wheelset if there is one that will work (if it is cheap enough).

Is there a way to replace the freehub body on these m475 hubs? Where would I get a longer freehub body and would that work with the wtb sx23 wheels lacing pattern?

My last option would be to take my old shimano 5700 10 speed group off my carbon bicycle and use it on the the touring bike set up.  I then question whether or not I could use my new 5800 front derailleur with my old crank set and vice versa...
This is an under-publicized and very frustrating problem. It works this way because mountain 11-speed cassettes have their largest cog attached to the rest of the cassette in such a way that it's suspended over the hub flange/spokes and not taking up any room on the freehub body. 

I have no idea whether any of the Shimano freehub bodies for any of their standard axle 11-speed road hubs hubs might be retrofittable to FH-M475. It's not impossible, because many of their hubs and freehubs are cross-compatible in a pinch. If it does work, the resulting hub will be some larger spacing than 135mm and will also have funny axle protrusion because of it. Also new Shimano freehubs for their nicer hubs can be kind of expensive. So it might be possible but it sounds like kind of a goose chase to me.

One Shimano hub that does what you want here is FH-CX75. Centerlock only. Last time I went looking for what you need, this was the cheapest reasonable quality option, but that may have changed. All sorts of cross bikes are coming at the moment with Novatec/Formula/etc hubs of this spec. Hope and White also have good upscale options.