Try calling After Dark Escorts.  They specialize in out calls.

Had a date cancel on me, due to schedule changes, and since I booked a room through Hotwire, I cannot cancel or change.  I figure I should try to make use of the room.  Is it possible to schedule a last minute date with a provider?  I'm new to hobby so don't have many references, plus hard to contact references on short notice...

Thanks for the tip!  

I tried them, but as I'm new, they needed a reference.  Also, as I'm new, I do not have many references, and could not reach any on short notice (would want to let someone know before I give out their info).  

So, decided to just let the room go.  I was really only in the mood for seeing the woman I had originally scheduled with.

Sorry to hear about your cancellation. And by the way, welcome since you said you are new, Id like to welcome you
In general, youre best bet is to just contact a few that you find nice. They can either say yes or no. As for myself, I am an outcall provider. I travel to any town and state in New England, New York State and of course Boston. I prefer getting a day or two's notice, but I tend to get a request on the same day. As long as you can give a few hours notice, most providers (including myself) can arrange the plan to get to you. As for reference, Most girls in New England do screening. As for myself, I am newby friendly. I screen my new clients, but do not require references.