This option is for the more adventurous at heart.
2. Renting A Loft
You can look into this at: AirBandB
If you use this search website, be sure to specify the dates, "entire place" and "real bed".
Then scroll though the listings and search for Williamsburg.
Here are some examples of listings I found:
Use the website to contact the apartment owners with questions, read reviews, and be sure to go over the rental agreements & security deposits. Each place is unique in it's arrangement.