You have several options, none of them great, but options none the less.
1) Uni-rig. The main may luff, but it will not be backwinded by the nonexistant main. You state that you have maxed out the jib traveler, but are still backwinding, there is no other full sail option.
2) Reef. You will have to modify your sail and take off the headboard to keep from damaging the mast as you sail, but this is the true best way to handle too much wind. It may be cheaper and easier to buy a smaller sail that will work. It will require the sheeting point to be equal to the full sail to keep from breaking stuff or requiring further modification to the boom and mainsheet. Also note, if you make the sail shorter than the spinnaker hoist point, you will not be properly supporting the mast (break it). With this much wind, you probably won't use the spinnaker anyway, but I wanted to point this out prior to breaking the mast.
3)Go get something to eat while waiting for the wind to back off a bit. Sometimes it is best not to leave the beach unless you have a safety crew (rescue) and lots of money to replace broken stuff.
4) Have Matt Miller sail the boat for you so that you can enjoy the view as he super pitchpoles the boat