Unfortunately it does happen sometimes - we actually have a spare cage set up to the point where all it needs is water bottles and water in them, chinchilla sand in the sand bath and food in the food bowl and we can have a ham living in there. Thats because I'm paranoid about our trio lol (When they have issues its usually without any warning and involves waking us from sleep to sort them. If we end up separating at 5am one night I'll want the least fuss possible.)
Theres a good chance the other two will settle down, its just been quite a big change losing a cagemate. Squishy will definetly settle to life alone quite quickly though, we've seen it with hams before
