During the week it won't be busy, but if any of your dates are on a Saturday or Sunday, thats a whole different kettle of fish, weekends at DLP are very busy generally, lots of local day visitors.
Just be aware that December the 8th is a holiday in some European countries (an official holiday in some and an unofficial one in others) so many Europeans have time off school/work around this time which may make DLP a little busier. However it will still be nowhere as busy as during main school holiday times so you should be ok. Personally I think the Christmas season is the best time to go to DLP so enjoy!!!