OP, I've been in an almost identical situation. What I did was skip breakfast, have the usual dose at 10am, and a light snack after the first punt. That saw me through to the end of punt 2, and i still had a lingering post punt semi.
I'm not sure what dose you take or the extent of your ED, but I take 50 mg generic viagra, and my ED is mild, so results may be different for you.