United Airlines is offering a very inexpensive fare of $359 round-trip between Boston and Hamburg, Germany. Fly in October & November, maybe later also.
http://www.secretflying.com/2016/07/boston-hamburg-germany-431-roundtrip/
The routing for this very low fare goes through Newark. From Hamburg you can take other ultra-low-cost European airlines (e.g., AirBerlin) to other destinations, including those with more temperate winter climates.
Other airlines may match this airfare.