1999 Pontiac Bonneville reluctantly starts then losses rpm until it dies

It is a very cold xmas morning and my 1999 Pontiac Bonneville started then the low
battery light came on and it immediately died.  I thought my battery was dead but after
numerous more attempts it finally started and the battery gauge was at normal but the
engine immediately lost rpm (within a min of starting) until it died.  so it starts then
losses rpm until the engine dies within a min of starting the car.  There are no weird
noises during any of this, it has plenty of gas/oil/etc. and it IS parked outside over
night, right now its about zero where I am at.