Canceling an interview?

[Vee2111]

I applied to two PhD programs. I was invited for interviews at both (but I have visited both in the past as well so I have an idea of what the programs are like) and the one that is my dream school accepted me a couple days ago following an interview last week. The other interview is next week and it seems like it will be a very formal, rigorous, multi-day process that I'm not really looking forward to anymore. I am positive that I want to attend the first school and I live very close to the second school so they didn't have to pay for my transportation to the interview or anything; they only booked me a hotel room along with the other applicants. Is it shitty to e-mail on Monday and say I'm not going? I have a pretty good relationship with the PI so I feel bad bailing on her but I don't want to waste anyone's time or pretend I want to go somewhere I don't while being interviewed by every professor in the department for two full days. 

Has anyone had a similar experience or can you tell me if I'm being a jerk by wanting to cancel?

Thanks in advance!

[TakeruK]

If you are 100% sure you are going to accept your dream school or you are 100% sure you will not attend the interviewing school, then yes you should cancel the interview. If you cancel, you might just waste some hotel costs (although they can probably get those refunded pretty easily). If you don't cancel, you waste that money PLUS all the time invested in you by interviewing you. It is acceptable to send them an email on Monday saying that you really appreciate the interview invite but you have now accepted an offer from XYZ school (or just "another school") and you would like to withdraw your application and cancel your interview. Apologize for the inconvenience.

If you are not 100% sure you are going to accept your dream school, then go through with the interview. Keep an open mind because you might still want to take this offer.