[dawonn]

If you google the data sheet for your gyro, it will tell you how much drift can be caused by temperature. They usually have a graph that let's you see the bias vs temperature which is usually a linear relationship.

An accelerometer will only help fix the drift in the roll and pitch angles, which are probably not helpful for you in FRC.

There are some filters which continuously estimate the bias though. One way you could do this is to apply a high pass filter that would filter out the bias. This will not solve all of your problems but may help some.

Your best bet is to try and think of a way to avoid relying on the heading for long periods of time.