In my area, snow and weeks of cloudy weather are common. Using around 10 watts of solar panel and a voltaic v50 battery it will only last about a week with no sun. The GTM does start back up when you press the button but getting to the button is a several hour trip to most of my relays. With the help of others on this forum I’ve modified the GTM to allow a small microcontroller to “press” the button once the sun comes out and power is restored. There’s details in the topic “How to make the unit stay on” and some in this one if you’d like more details: Idaho mountains goTenna mesh experience
They wake up looking for their paired device and are still a relay and endpoint. If I can message them I know the area is covered for communications.