If your bike has 700c wheels and your rear rack is not a low rider (for example Tubus Logo compared to the Cargo) you will have no problems. If you have 26" wheels and / or a low rider rear rack or you aren't comfortable with your clearance from the ground you can easily remount the pannier hardware a couple of inches lower, which raises the mounted pannier.

Your biggest problem will be keeping yourself from taking too much junk because of TT84's enormous capacity - 84 liters (obviously). If you do take enough stuff for two people and you are a little heavy to boot, you will want to make sure that your real wheel is up to the task. I can't imagine that you'll need front panniers though.