You need to find out how the company is being stuck off.
Is it being struck off involuntarily (by them not filing accounts) or are they trying to go the way of voluntary strike off.
If they are going the way of a voluntary strike off, part of the process is them saying there are no assets or liabilities and making a declaration to that effect. If you are owed €15K, then they cant really go the way of voluntary strike off as there are liabilities.
Do you know exactly what process they are following?
I would just make sure they are doing everything by the book.
If they are being stuck off involuntarily, you may be better taking the €5K.