Someone please correct me if I'm wrong, but I do not believe that they give out extensions... but I don't think it would hurt to ask. I'm not sure if there is any real risk of them taking away your admission. I kind of doubt it, especially if you just call in anonymously...
If I were in your shoes, I'd probably just man up and pay the deposit, and then wait for the other schools. This way I'd know that I was into atleast one school regardless of what happened with the others. And if I got into my dream school, I'd just pull out and lose the deposit. This way I could sleep easy.
I'm not sure the best way to go about asking for this extension. But I would recommend that you probably call in (anonymously) and see if it is something they would even consider. Ask "I recently was admitted to your program, and I'm very excited. I'm waiting to hear back from a couple schools and know that the deadline to put down the deposit is coming up. Does your team and the admissions committee ever entertain requests for extensions on this deposit window." or something like that. Just don't tell them your name, and that way you can rest assured that they will not look at your negatively for any reason.
let us know what they say!
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