I've been on some group rides where it's been necessary to "improvise" some interesting tire/tube combo's... Although I haven't done this exact setup, I'm pretty sure it will work out.

The fact that most 700x32 tires run at 90 psi or less is one factor that will work in your favor. Just make extra certain that the x23 tube doesn't get pinched under the tire's bead.

Let me know if I turn out to be wrong, OK?