Geography and political common sense are against the North Colorado-advocates. Eighty percent of Colorado's oil and gas revenues is from NoCo. While some say this is a great reason to break off it is also a great reason for Denver not to let the region go. NoCo also uses about 80 percent of the state's water due to agriculture practices. As a state NoCo would have to obtain water access by negotiating with other states including Colorado. This is something not likely to go well for an independent NoCo.
Even if Denver were to allow NoCo's separation, NoCo would need congressional approval as well. There is no way congress would give its blessing because then separatist groups in California, Oregon, Washington, Michigan, and elsewhere would start pushing hard for their right to break-off.
Only two states have even been spun-off existing states. Maine gained separation from Massachusetts. It took Maine's abandonment by Massachusetts during the War of 1812 to give pro-statehood people enough credence to even start a movement and then it took the threat of civil war and the Missouri Compromise to give Maine its freedom. The other successor, West Virginia, needed the Civil War to break off from Virginia.
It will take civil war or the threat of civil war for North Colorado to become a state. Until then NoCo will always be a part of Colorado so there is no need to pay any attention to this statehood debate.