I live in the "Vail Valley" actually in Gypsum.(25 miles west of Vail proper) The second week of October is hit or miss as far as weather goes. Chilly to cold mornings over the pass. (Low 30's to low 40's in the early hours) Daytime highs are perfect for riding. Average in the mid 50's to mid 60's.
The hit or miss part comes in because Halloween is usually our first snow. (Kids in costume covered by jackets [smiley=nixweiss.gif]) Weather reports closer to your travel time will be key...and always remember, snow can happen anytime on the divide. (My first year here, 4th of July fireworks were cancelled due to snow. Rare, but it happens)
If you do choose the northern route and want a riding partner for a section or need a free place to crash for a night or two, PM me or call me (970) 445-8191.
Good Luck, Rick