I live over the mountains from you and believe me, 30° isn't cold with regards to glow engines. We regularly fly in temps MUCH colder than that without problems. Here's a couple suggestions in addition to the ones already offered.
Use fuel with a higher nitro content. Smaller engines generally perform better with more nitro, try 15%
Re-tune the engine, colder weather often dictates a richer mixture
If it's still hard to start, put a couple drops of cigarette lighter fluid into the carb before you start it
Try a OS #8 glow plug
Oh, did I mention to use fuel with a higher nitro content, nitro is your friend
There's no reason at all that your engine shouldn't run great even at temps into the lower teens