OTA Update Esp8266 without IDE
This: https://github.com/arendst/Sonoff-MQTT-OTA-Arduino is a Arduino based firmware with support for OTA. It's written for Sonoff, but that is just a ESP8266 with a relay attached, you can easily adapt it to any ESP8266.

It uses a 'hard coded' address of a web server where it downloads the firmware, and updates are triggered by MQTT messages, but all of that should not be too hard to change to something else.