We're in northwest Connecticut, which has similar temperatures to the Buffalo area. Fortunately, we're just far enough east to avoid lake-effect snow.
We'll see overnight temperatures into the 20s during the month of April. Since it warms back up during the day, freezing has never been an issue. Water lines won't freeze the instant it drops below 0 degrees Celsius. We had the fresh water hose laying on the ground freeze once, but we don't generally venture out if it's going to be that cold.
We've been to Maine in early May several times without issues. If you're really concerned, pay attention to any place that water lines might be exposed to outside temperatures. Maybe open the low point drains, and leave them open so if any water does freeze it has room to expand.