Yes, if it’s a localized disaster it might work. But, if it’s a big or national disaster, it won’t help them
If it’s a huge disaster it will take longer to organise but the idea is JWs just outside the affected countries will take in displaced JWs. Yes internationally if needed but as close as possible. It could be a long way away.
The branch offices have disaster relief committees set up and they all have trucking departments ready to bring aid or bring people out. Even flights or boats. The transport department is experienced at getting fast visas and papers for all missionaries who sometimes need to be moved quickly.