At my school, we have a two day week before we are out for Thanksgiving break.
I have my Spanish 1 students answer questions about their own Thanksgiving celebrations & make their own personal turkeys to display the things for which they are thankful. Everything is done in Spanish. The students love telling about themselves and celebrating holidays, so we both win - they have fun, and I get to see them use Spanish!
For my upper level students, we read a passage (all in Spanish) about Thanksgiving. There are pre-reading, vocabulary, and comprehension activities to accompany the reading passage. The students love that they are using Spanish to discuss & celebrate a cultural holiday.