Point well taken. Most interviews I've been in on, from either side, have been over the phone of late. I live in San Diego, based out of San Francisco, and our recruiter is in Chicago right now. It is much different from the small-group startup culture I used to be in where everyone was in one office.The only issue with asking HR or a recruiter is they may not know. In my firm our recruiter is 400 miles away and the culture of each office is slightly different.
And, come to think of it, the startup I joined on the way to working at a large company interviewed me over the phone and never asked me to come in before extending the offer. My direct manager was also a remote employee and didn't think it was worth both of us traveling to the office.
The world has changed. But I'd still be most comfortable in a suit I KNOW is flattering if I had to go into an interview blind. Better to look good even if you're more dressed than the interviewer.