Have switched to the ESP8266 -12F for a couple reasons, the exposed ADC and deep-sleep access control.
Using the DHT11 with a one minute sampling rate with 2 AA NiMH freshly recharged batteries, I get 4823 samples with a voltage degradation curve below. At 2.61V, the reporting to thingspeak still occur, but temp and humidity are reported at value 0.
This just gives a rough idea of battery capacity, and as deep sleep interval grows, the sample count should decrease based on the ~20uA current required by the device.
In terms of range to an AP, I am measuring about 140feet max with two walls between devices. Using the Android "Wifi Analyser" app this seems to be in the range of -80-85dBm.
When out of range, the wifi manager will boot into an AP host mode for configuration of all parameters. So if configuration needs to be changed, either device need to be moved out of range or reset when AP is off. A problem with this solution is that if the AP host is down for any reason when the ESP8266 tries to connect, the ESP8266 will stay in the AP host mode until properly configured, or the ESP8266 device is rebooted when the AP is available.