Oh boy, don't say a thing until they make an offer!
First, it would look extremely bad to start negotiating on your offer before you received it - do not do this!
Second, you don't even know what they will come back with.
Just wait. Don't count your eggs before they hatch. However, when/if they do make a final offer, you can absolutely say you received a 2.2x offer from another company BUT you really want to work for them...tell them if they can match/come close to that offer, you will sign on the dotted line.