My wife and I and our two kids do a fair amount of back-country white water rafting. After arriving at a very remote take-out with no car and no cell service after a five day float (and running low on food and water), we went ahead and bought an actual satellite phone. It’s a game changer. Cost about $400 used and we have it refreshing quarterly on BlueCosmo for $99. It’s awesome, and cheap insurance relative to the risk.