If you are able to easily overpay your mortgage and subject to fixed mortgage penalties, look at reducing your term to maximise savings on interest repayments.
Is the €8-10K paid off the capital or held in the account in reserve? Making sure that the former is the case and then keeping your repayments at their "normal" level will reduce the effective term of the mortgage and yield the best savings possible. See Karl Jeacle's mortgage calculator for more on how such accelerated repayment strategies can significantly reduce your long term interest costs.