The best time to adjust your coverage limits is before the trouble happens–whether its theft, fire, or another catastrophe.
Once the damage occurs, the coverage limits in your home insurance policy will be the maximum you could receive to cover damages. If your damages amount to more than you're covered for, you might need to consider dipping into your emergency fund to cover the difference.
Don't just hope you're covered; know so. Talk to an Allstate insurance agent before trouble hits.