Bonjour and welcome to planDisney!
It sure sounds like you have a fun 40th birthday trip to Disneyland Paris planned which just so happens to fall over New Years Eve.
My family stayed at
Les Villages Nature Paris a couple of years ago and we all absolutely loved it! It truly offers the best of both worlds, the opportunity to relax in nature, whilst at the same time, being only a stone's throw away from the magic of Disneyland Paris! My daughter still talks about the Aqua Mundo water park, Bellevie Farm and Forest of Legends outdoor play area to this day.
I have to tell you that the week between Christmas and New Year is an extremely busy time to visit Disneyland Paris and it is not uncommon for the parks to reach capacity, especially on New Year's Eve itself.
I think if I were you, I would plan on visiting on New Year's Day. A 2-Park ticket will give you greater flexibility and as Disneyland Park and Walt Disney Studios Park are within walking distance of each other, you will have the option to come and go, between the two, as you please.
The reason for me suggesting New Year's Day is because New Years Eve will undoubtedly see large crowds with most Guests staying out late, to "see in" the New Year. If you aim to arrive prior to park opening, you should find that the first few hours will be quieter due to many Guests who were there the night before having a lie-in / later start to the day.
When visiting during busy times, I always like to have a game plan. Make a list of your must-do's and get these checked off first and plan to see shows in the afternoon, when crowds are likely to be higher. The good news is that
Disney Tales of Magic nighttime extravaganza takes place nightly (weather permitting) so no matter which day you decide to visit, you won't miss out on the amazing fireworks!
If you are wanting to experience as many attractions as possible, I would definitely consider purchasing
Disney Premier Access Ultimate which would allow you to access each eligible attraction, via the fast lane, once, at the time of your choosing, during the day of your visit. This would vastly reduce the amount of time spent waiting in line.
Similarly, you can also pay to
guarantee access to shows and
book the reserved viewing area for the parade and nighttime show. Although each of these come at an additional cost, it will enable you to experience a lot more of what is on offer during the day of your visit whilst also minimising queuing.
I do hope that this information has been of help and that you have a wonderful trip to Disneyland Paris later this year.
Wishing you a magical holiday filled with memories which will last a lifetime!
Emma