Warping on a budget

I'm ready to create my first warp.  I'm using a box loom, not an inkle loom. I don't have a warping board, and none of my chairs have straight legs.  I could build a warping board, but then (ah yes, the catch) I would have to find a place to put it.  So instead I am buying this set of four 12-inch tall clamps to use as a warping system.   They are relatively cheap ($27) and are small and easy to store.  

I can warp small things like headband trim on my 4-foot wide desk, and larger things, like belts, on my folding 8-foot sewing table.  I'll use the 4th clamp on the bookcase behind the sewing table to get another 4 feet of warp.  That's the plan, at least.  Let's see if it survives contact with reality-- many plans do not!