Unless you are in uncommonly great shape and used to riding a lot of elevation all day (like our buddy Spaghetti Legs) gears are your friend. The 30-27 combination on the McLean is pretty close to 1:1, which is what I aim for on truly hilly and long rides. Also, a lot depends on how the elevation gain happens- long 5-7% grades, or shorter, more agressive 10-18% grades? On the former (like Thunder Ridge) a compact with a 25 rear cog will do the trick. On the latter (like the Dairyland Dare) you need a small granny triple or the double equivalent like a 34-34.

Regardless, good on you for having the courage to try this ride even though you question the foolishness of same.