This Saturday I will be smoking my first turkey. I am using a Masterbuilt propane smoker and I'm smoking a 21 lb. bird (I know but it was given to me). I will be soaking it in brine it for at least 24 hours. My question is what temp should I cook it at (was thinking around 250-275) and how long? I'm thinking at 250 it's going to take me roughly 10 hours to cook this thing. ANY advice will help.