TTGO T-Beam V1.0 & OLED & deep sleep needs proper power design

Hi!
I’m new to both ESP32 and Lora, but very interested in what the possibilities they offer.
I’ve been searching randomly for a good, cheap board for testing range etc, and later consider setting up a gateway at home which I can reach from my boat.

I’d like to use a 18650 battery (or similar) and TTGO T-Beam ESP32 was the first thing I found which also had a battery holder. When I learned about Lora I read 5+ years of battery life, but it seems like you’re lucky with 5 days with a lot of the current devices, as long as they don’t catch fire.

Is the TTGO T-Beam the way to go? I like that it has GPS and display, which is nice for testing, but for a permanent sensor setup, I’d like something as simple as possible with Lora + I/O for a few sensors like temperature and wind etc.