There will be plenty of parties going on but one thing I notice is that you are arriving December 25th, unfortunately this is a bad time to be looking for accommodation.
Traditionally the tourists get to the beach areas before Christmas (another reason for a party) get a bungalow and settle in. If there is no 'trouble' in Thailand these beach areas will quite often be full to overflowing so finding a bungalow/room can be hard even in areas away from the parties.
Even in the KSan rd area it can be difficult to get the accommodation you prefer and you may have to take something more expensive or 'seedier' than you like.
If you are prepared for and accepting of this then you will have a fun time, if you spend too much time looking for that perfect accommodation you will miss all the fun ;)
But then luck can always be on your side and you may walk into the perfect place at the perfect time
Or there may be another airport blockade, riots in the streets or whatever and then there may be plenty of rooms to pick from, check back later.
Have a good, safe trip :)