Hopefully I'm not too late to the party, but I will give my experiences in this area so far. Moved here (NJ) about a year ago, mid-transition, and I still to this day have no letter. I got in under the WPATH alternate-route --ie live at least part-time THEN go on hormones. You can also do informed consent, where you just sign a waiver after they explain all the risks of hormone therapy.
Mazzoni does both alt-route and informed consent. If you're living full-time now, there shouldn't be an issue. I'm in the process of transferring my care to them now and they've been nothing but helpful. I've heard from other guys that they were able to do informed consent, go full time and then visit one of their psychiatrists to get a top surgery letter very quickly.
If you are low-income, talk to Mazzoni about sliding scale. My appointment is going to be $20, but they do not turn anyone away if they can't pay. It will literally cost me more in train fare to get there than for the appointment. They schedule 2-3 weeks out for new patients - ask for Dane Menkin. He's a nurse practitioner but I hear that he is the best working with trans guys.
I know that most people go to therapy first, then hormones, but your & my situation is pretty common especially among younger guys. Some providers are not comfortable with prescribing if you don't have a letter and many are very vague about whether they strictly require it. McGinn moved from being more loose to being super-strict on letters for T and top surgery, and I wasted a trip out there because I wasn't aware of her policy. Don't be embarrassed about just straight-up asking if someone requires a letter if you're full-time. It'll save you a lot of time and aggravation.