My experience is that if you are willing to mess around with a variety of racks and panniers you'll probably get something to work on a cyclocross bike, but:

- it may result in poor handling because the panniers are way back of the rear axle
- you may not get the size and type of panniers you want
- you may not get the rack you want
- its going to be a lot of hassle

Some other options are:

- use a BOB
- buy a used touring bike use it and sell it
- buy a new touring bike use it and swap the parts over to a cyclocross frame when you get back
- buy a Surly Cross Check, buy a Long Haul Trucker fork for it, use front panniers and either none or small rear panniers, when done the tour switch back to the Cross Check fork
- buy a cyclo cross bike & buy an Old Man Moutain Cold Springs Front rack, use front panniers and either none or small ones on back

To give you a real world data point I am riding a Surly LHT 58cm frame Old Man Mountain Red Rock rear rack and Ortlieb Bike Packer Classic rear panniers with 175mm cranks and size 45/46 (~US11) shimano SPD sandals. With the cranks at horizontal and the panniers set midway on the rack I have 2.5cm of clearance. I do have room on the rack to move the panniers back about 4.4cm, but that is going start causing some problems with handling - particularly if there is no front panniers.

Good luck on your trip - you'll have a blast!