Any thoughts from the MOM crew? http://http://www.motoringalliance.com/forums/cooper-s-engine-drivetrain/20480-r53-engine-runs-very-rough-cold-weather.html#post232595
The MoM crew will tell you the same thing except they may add have a cup of coffee and a donut while your car is warming up.
These cars run very rich and in cold weather even more so. The flashing check engine was a misfire. You may have fowled a plug with fuel. I've seen it have on my own car. I would throw a new set if plugs in and if The wires are old swap them too. ALso look for rust on the coil terminals.
^^ Yes I for got about that ^^ Look on # 3 of the OEM coil and even scuff them with sandpaper if you need too. Note the OEM coil is still the best coil to run and the OEM wires are just fine also. No need for MSD or other wires because stock works perfectly even in race cars.