[contingencies]

AFAIK mining doesn't actually require connectivity until you want to reveal the block. It's unlikely anyone else will discover it quickly, so you can just have someone walk across a border (or get on a flight) and plug it in to the global network from elsewhere.

[mason55]

Blocks are supposed to be found every 10 minutes (difficulty adjusts to maintain this average). Theoretically someone would find the next block 10 minutes after you found yours and they would broadcast it. Then the next block would be found on top of that one. So unless you could get your block broadcast in under 20 minutes your chain would end up as shorter than the other one and wouldn't be counted as the main chain and it would quickly die.