It is relevant to the issue of her housing needs!
If you are waiting until January then the Grounds for the divorce will be the Five year Separation not Unreasonable Behaviour.
You certainly should not allow it to be repossessed as that will simply cost you more!
The first option is to wait until you have started the divorce proceedings and apply for the financial issues to be dealt with then and seek an Order for the Sale of the property
The second is to make an applictaion under the Trusts of Land and Appointment of Trustees Act for an Order for sale using Property Law.
If your ex then decides to issue Divorce Proceedings against you then the money spent on the TOLATA proceedings could be wasted if the matter is then dealt with within those proceedings.
The sensible first step would be to try and discuss matters with her using Family mediation
to see if any agreement can be reached.
Please ask if you need further details