average lifespan on "Good" batteries is 3-6 months depending on usage, settings (and as stated temperature variance). A cheap/off brand battery can have a lifespan as short as a few weeks with the same kind of usage pattern.

High milliamp hour rechargeable's will generally last the longest based on their drain (output voltage) characteristics versus standard alkalines. For non-tech people reading this, rechargable batteries output a nearly constant full voltage output rating throughout their life/power span (milliamp rating) and then die almost instantly when they are out of power. Alkaline's decrease in voltage output at a fairly steady rate until the power required by the device is greater then what the battery can provide. What you will find is if you take dead (alkaline) batteries from a remote and put them in a less taxing load device you can still use the batteries for a while (rechargeables you can not).