Use Heat to Improve Humidification Effectiveness
Another challenge of using a CPAP humidifier is that the moisture can condense in the tubing. The combination of cold air and higher humidity settings makes this more likely. This keeps the moisture from reaching your nostrils.
You can increase the amount of moisture that reaches your nostrils by adding heat to the line. If you don’t currently have a heater for your CPAP, consider adding one. If you do have a heater, you might use other strategies to make sure the line stays warm enough. You can pass the CPAP hose under the blankets with you to help it stay warm. You can also get insulation for your tubing to help it stay warm.
Regardless, if you notice condensation in your CPAP tubing, make sure your humidifier is lower than your head so that liquid water will flow back down to the reservoir and not into your nostrils.