Flight
Denver will be the closets airport. If staying in Boulder: Airport is approximately to "Downtown" aka Pearl Street Mall in Boulder is 45 minutes driving depending on traffic. If staying in Longmont: Aiport is approximately 45 minutes to Longmont mainstreet depending on traffic.
Travel Note
Feel free to stay in Boulder or Longmont. Both are equal distance to the venue. Getting an Uber/Lyft to the venue should be easy if you're not driving. Leaving the venue we'll aim to have a shuttle to Boulder and Longmont to simply getting folks back. Uber and Lyft should still be accessible and the shuttle just helps smooth the exit at the end of the night.
Hotel
For guests choosing to stay in Longmont, other guests will be here and will try to arrange a shuttle from the venue back to this location.
Travel Note
Embassy Suites by Hilton is a good option with some staying there. In general, there might be some more hotel options in Boulder compared to Longmont with University of Colorado (CU) in Boulder.