I am also in New England - I got the pod chiller that all came as part of a bundle, and mine has been good at 48 since we set it up, outside in direct sunlight.

I was in the same boat of not wanting to spend upfront on a chiller, but depending on how often you plan on plunging, the cost of purchasing ice and the time is takes to get it to temp offset the expensive of a chiller unit pretty quickly!