Only you can say if that trade is a good one, especially as you will be $1050 cash in on the deal.
I am not sure losing a good zoom in exchange for a 40mm pancake is really all that great, and yes, you are going to be a little hard up on the wide end. Even adjusting for the wide-end help you'd get from the FF sensor, you'd still be missing out on whatever you used to do between 17mm and 25mm on your old lens/camera combo.
Perhaps you should also add in the cost of the wider glass you may find you will want to buy?
I am in kind of the same situation. I might like to go FF, and I probably would if it was "only" the considerable cost of the camera body. The kicker, though, is additional cost of the new walk-around zoom I'd need to shell out for (24-70 or 24-105 or something), or maybe 2 or 3 primes instead.
I agree with the others that say if you do it, do it right. You should be sure you have bought enough good glass to make the FF camera work well for you.
Good luck. Unfortunately no real camera deals on B&H "Black Friday."