Will E70 support 12.5 to 1 on the street?

I am told E85 will not be available until sometime in May in our area. I am close to being able to run this thing. Besides having to go leaner, can I run E70 until E85 is available. Have it up the road. Other option is a blender pump site 80 miles away, and possibly fill a couple drums. That is if it blends correctly at 85%.