Will it be easy to find accommodation in Banglampu,Bangkok,on January 1st?

Christmas time and the New Years period is peak season in Thailand so expect most hotels and guesthouses to be busy. The rates are usually at their highest at that time of year. Many people book in advance to avoid disappointment and hle when they arrive. If you are flexible and easy going then you should be able to find a place. If there is a particular area you want to stay in and don't want to waste time looking for a place to stay then i'd advise you to book in advance.