I know what you mean when it comes to shopping for 235/65-17 tires in an A/T design. All but non-existant, then expensive when you do find them. I ran Toyo Open Contry A/Ts in that size, and was quite happy with everything except how long they lasted. I only got about 40K miles out of the 50K tires...
As for your question, the 245/65-17 size is only about 1/2" taller, and less than that wider. Unless your springs have sagged a great deal, I would think you would be fine.
Most tire shops will mount them up for you and you can take them for a spin in the parking lot to see if you have any rubbing issues.