Ah! I started a similar thread in the General forum, and continued in the women's regarding the 'farmer' approach.
What I've found, after much research: Astelin, which is prescribed for exercise-induced vasomotor rhinitis. Works okay, but not great. Tried Claritin-D, 12-hour. Worked, but still ran through a pile of tissues on my ride, it made me thirsty, and it might have made me a little ditzy. Finally got a prescription for Atrovent nasal spray. I carry Atrovent puffer for cold-weather/exercise-induced asthma, but very, very rarely use it. The nasal spray versions seemed to work amazingly well. Sunday was my coldest ride yet (okay, it was only in the 40's) and it normally would have been a complete, non-stop run, but I just had a few sniffles. Of course, talk to your doctor first, but the Atrovent nasal spray (NOT the asthma-inhaler puffer) really worked well for me.