First off, there is no way to stretch Pacific Dunes to 7,100 yards from any tees we built. If there were a set of "Doak tees" they would be shorter than the current back tees.
However, there are a few tees we built just for certain conditions, as Dan alludes to. The tee for the first hole (behind the 18th green, very near the windscreen for the patio) was built for winter downwind conditions; the hole is 400 yards with 290 to the crest of the fairway, so it was never intended to be used much.
Other tees not on the card:
#4 and #13, there is a tee near the snack bar which allows either hole to be played at about 500 yards. It's really for #4 in the summer conditions, but it's not as pretty as the tee out on the point at 460 yards.
#5, there is a tee up on the right, making the hole play only 100 yards at a funky angle, at Mike Keiser's suggestion.
#8, you can play off the back of #8 at Bandon Dunes, which adds about 20 yards.
#11, we leveled out a spot on the apron behind the sixth at Bandon Dunes, so you can play from there at about 170 yards.
#12 can be played from the back tee on #5 ... no longer, but shortens the walk, as long as you are a gentleman and don't play down #4 fairway.
#15 has two small tees way up on top of the dune near #3 green ... a much longer walk to play #15 shorter but at a cooler tee shot angle. These are mostly overgrown by gorse now, since no one ever detoured up there.
#18 has its back tee just above the 17th green on top of the dune, which is 661 yards.
Mike Keiser has suggested a couple more back tees with some prodding from his USGA buddies, but I've discouraged him from adding any more tees for now. I think Pacific is more highly regarded by club professionals and by Tour professionals BECAUSE it is short enough that they have a chance to shoot a reasonable score in the wind, and a low score on the rare calm day.