Hi Trumic,
I have some insights and guesses for whatever they're worth:
1. Personally I'm working this January. However, due to being busy in December, and also having time off for holidays (Thanksgiving, Christmas) with family, I would say I turned away more bookings than usual.
2. I haven't been to DC yet, I plan to visit this spring sometime (Currently slated for May but I may be able to come sooner). However there are places I go often such as Denver and Chicago, and I at least for me, I consider cold weather, possible snow, possible flight delays when planning to visit places where there is a proper 'winter' (unlike Los Angeles where I'm based and weather remains fairly mild year-round).
3. I have heard from others in the industry (directly and also in forums, reddit etc) that January is 'slow'. I haven't experienced that myself, much to my delight in January I'm busier than ever (that is also probably due in part to me building my business, reviews, etc over these past 8 months since I started). So this is just a guess/ possible explanation - if some providers think/ have experienced Januarys to be slow, they may specifically plan their vacations (or other actions requiring downtime, whatever they may be) around this (perceived) slow season.
I hope this helps - happy hobbying!
xo xo
Alyna