The Fargo fork has a 442mm axle to crown length and the Casserole has a 383mm axle to crown length.
Thats a 59mm difference in axle to crown length, which is huge. I would not advise it.
The Salsa Vaya fork is a little better, with a 405mm axle to crown length and a 50mm or 45mm offset, according to here:
http://salsacycles.com/bikes/vaya/
I know that the Vaya fork will be available next year, I would ask Salsa if the fork is a match for the Casserole.