"We made it back home after a safe and rewarding trip abroad to both England and Paris. Thanks to you for all your help in this undertaking. The field trip takes an extraordinary amount of work to make it a successful time. Your efforts to make it all work out for us are sincerely appreciated. We were so glad to meet you to "put a face" to all the notes and information that you sent us.
It really is nice to be back home with everyone safe and back to the routine work of school and home, but it was wonderful to be in England and Paris again. Already we have spoken of what we will do "next year." I hope you have a wonderful day, week, year....you're just wonderful to work with.
All the best to you and the most sincere gratitude."