You could email them to ask. I would guess any and all places email instead of like USPS mail, they want to get yes/no's fast and snail mail doesn't do that.
For all that care, TAMU's number theory group has filled it's 5 spots. Also I emailed IPAM and MSRI to be told, essentially no. That is they sent out first offers already.
Last year I got my responses (along with a few other people I know) in late feb (like 5ish days from now) to early march. Don't worry, you got this! Also on 3/9 a lot of spots will probably open up.
UCSB also started to send out acceptances, some got them a few days ago, I got mine today.
Last year many programs I did not get in did not reject me, not in a timely manner at least. After I got an offer and it was the last week, I started to email some places I applied to and got a response...
Judging from my results, I think UMN is the hardest out of the 3 to get in then Oregan/Potsdam. I say this b.c. I was shortlisted for the last two but not for UMN.
I emailed them last week asking if I should accept other offers or I may get into their program and they said I'm on the shortlist and I will hear back by the 8th.