If your parents dispose of the house now, there will be an exposure to CGT. Even if they give it to you, you will have to put an open market value on it.
You won't have a CAT liability on it.
If you subsequently dispose of the property, you will be faced with a CGT bill on the increase in value.
If your parents leave the property to you in their will, they will have no CGT as disposal on death is not subject to CGT. I don't think it's subject to stamp duty either.
So the problem is that your parents are short of cash at the moment.
Have you spoken to the lender? They might switch it to an interest only loan so it would only cost them around €6k each year. You might be able to switch the loan to another lender if the exisiting lender does not agree.
Why don't you lend your parents cash to be repaid out of the proceeds of the estate? This preserves the property in their name and so avoids the CGT problems.
If you wanted added security, you could buy a portion of the property now - say 10%.