I didn't even think of a spare tablet. They have come down so far in price, that would be an option too. And open Wi-Fi is so prevalent, IF he needed to use it for any reason (for the sake of exploring this as a possibility), he wouldn't need to do so at his house or the park.
I left an abusive relationship once, so I have some experience in having backups. It wasn't very difficult when I did it, so I assume the options are probably better now. You just need to be careful not to "contaminate" your phones, etc. But again, if a person just wanted to get away for a short time, needed some head space, they wouldn't need to do anything elaborate. They would just need some protection from the elements, something to filter water (a Sawyer Mini runs around $20, so that wouldn't be noticed) and say some lightweight food (which people who are into the outdoors probably have/keep on hand anyway, so purchasing that/consuming/accounting for it, wouldn't be easy to track.)
I left an abusive relationship once, so I have some experience in having backups. It wasn't very difficult when I did it, so I assume the options are probably better now. You just need to be careful not to "contaminate" your phones, etc. But again, if a person just wanted to get away for a short time, needed some head space, they wouldn't need to do anything elaborate. They would just need some protection from the elements, something to filter water (a Sawyer Mini runs around $20, so that wouldn't be noticed) and say some lightweight food (which people who are into the outdoors probably have/keep on hand anyway, so purchasing that/consuming/accounting for it, wouldn't be easy to track.)