...the couple died of hypothermia..
...did the daughters not visit them and know the conditions they were struggling in...the wife was immobile and her husband was obviously struggling to care for her...there were no carers visiting..?...and the house was found in disarray as if there had been intruders/burglars..?...it’s all very strange and I would say needs lots of questions asked...that would surely be the priority before inheritance thoughts...