But when we’re talking antennas, do I need to get a big one that I need to try and get above the tree line, or does it boost signal penetration?

I have a question about how easy the signal is to block. I live in a somewhat mountains, densely forested area. Do devices need to have direct line or sight to communicate? Wanted to set this up as a potential back up communication source for grid outages and keep a device in each car.

Did not know this fork exists. Thank you for enlightening my day, Internet stranger.