Range is very dependent on power, antenna size & configuration, and bandwidth. Obviously more power can throw a signal farther, and a bigger antenna can pick up a weaker signal. A directional antenna can transmit farther and receive weaker signals than one that is omnidirectional. And the narrower the bandwidth, the greater the range but the slower the data rate.
To improve the WiFi signal on my farm, I set up an outdoor-rated access point (TP-Link EAP110-Outdoor) high up on the side of the barn and I have it configured to use only a 20 MHz channel width (most APs default to 40 MHz or 20/40. I also have it set to use channel 1, which as the lowest frequency has slightly better range than higher channels. 835 feet away at the end of my driveway I get -76 dBm and 36 Mbps, not super but way better than Sprint. I'd probably have an even better signal if the barn wasn't covered in galvanized steel panels and if the AP wasn't on the side facing away from the driveway.
I wouldn't be comfortable doing that due to rain. I guess it depends on how severe it would be. ---
