Bernie,
Karafun allows you to store 1000 songs in your device (iPad, for me), so even with no wifi - you can have a staple set of favorites ready to go on a desert island ... assuming you have a battery powered speaker system, of course. For the odd request that falls through the cyber cracks - you can use your phone as a hotspot. Of course, a strong wifi connection is preferred, but there's always a workaround.