Not necessarily next year but a general suggestion to join at an undefined future event.
"The whole family thing" is referring specifically to the traditions of extended family visiting. Typically the construction of "the whole ______ thing" is generalizing the experience that fills in the blank. "The whole school thing" might be used to refer to the overall standard or average experience of education (grade school, secondary school, university, etc). "The whole meal thing" might be used to refer to the standard or average eating process (cooking/prep, table settings, handwashing, eating/table manners, clean up, etc).