Travel with 1 uni 2 wheelsets?

I just acquired one of Jacobs fatties. I like to take a unicycle with me when travel. It would be nice to travel with a fattie and a road uni but that is not practical. I’m considering making up a 29 inch road wheel that would fit my 26 inch fat frame. However my flansberrium has a 125 mm hub which I’m pretty sure means my alternate 29 inch wheel would need one too.
Just how bad an idea is this?

Excellent idea

I would build them both up with disk hubs.

The only downside of using the fatty frame with a 29" wheel (with internal disk) would be the risk of knee-basing from the wide frame but Jacob did a fine job of minimising that risk with his rounded crown design.

I have done a fair bit of travel with a 26 and 36" wheel and 36" frame.

You don’t get a huge improvement over just bringing two separate unicycles. The part that’s duplicated – frame and saddle (and whatever attachments) don’t weigh a lot or take up significant space compared to the two wheels and first frameset. If weight and space are really, really tight it’s a good idea, but if you can manage to bring both, it’ll be much more convenient once you get there.

That’s 1-2kg of excess weight and bulk, depending on the frame and type of seat.

I managed to get all three of my race Unis to Unicon 17 (700c standard, 24" standard, 26" MUni/Cyclocross standard) with one frame, and all my luggage + tools for ~15kg. It’s great being able to travel with multiple Unis and not get charged excess baggage.