Don't the non-Opec producers, eg in North Sea, Alaska, Canada hv enuf oil to counteract supply cuts by Opec?

It seems that, w/ Kuwait & Iraq possibly excludible, OPEC now has less margin to play with in decreasing total production; most members won't reduce production below a certain ceiling, or else imperil their "minimum projected income" despite increased prices. In case of OPEC supply reduction, can't producers like Britain, Ireland, Norway, Canada, Alaska & perhaps even Russia get together as a counter-consortium to take up the slack (if Iraq & Kuwait are removed from equation) ?