On January 17th, a representative from the show stated, "It is true that Park Yoochun and Yoon Eun Hye gifted a trip to Thailand to all the staff members. It was to thank all members who did a great job in the cold weather."
The actors paid for a five-day, four-night trip, most of which was paid for by the actors themselves and a portion of which was paid for by the production company. The staff will leave for Thailand on either January 20th or 21st, but it doesn't look like Yoochun or Yoon Eun Hye will be able to join them because of their schedules.
"I Miss You" wrapped up on January 17th. Did you catch the last episode?