They usually don't go far as you know, but sometimes they will get far from their cage. When my butter went missing from the rack in the living room, I found her under the kitchen sink which was pretty far away. My cinny went missing for months and was eventually found 10ft from her tub.

Just don't give up hope, sometimes destroying an apartment to find them just makes them go farther or you miss them in your frantic search.

I personally think the flour trails aren't very effective and are just a huge mess to clean up. Take a deep breath, keep traffic in the room low if possible and occasionally check along the walls when it's dark out. They usually won't pass through the center of the room and will move along the walls. That is also a good method for searching, get down on the floor and follow the walls.