<<<From what I’ve seen from Roman Catholic posts on this topic it isn’t considered adultery if the couple isn’t have sex.
Jesus teaches that the Marriage bond ends at death. (Luke 20:23-33)
I have seen some Roman Catholics take the position that even then you cannot remarry without it being adultery.<<<<
That is not the Catholic teaching. If someone posted otherwise they needed to cite it properly: See below.
<<<
Canon law states:
CAN. 1055 §1.† The matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life and which is ordered by its nature to the good of the spouses and the procreation and education of offspring, has been raised by Christ the Lord to the dignity of a sacrament between the baptized.
Code of Canon Law: New English Translation (Washington, DC 1998) 335.
Paul in 1 Timothy 5:11 explicitly acknowledges remarriage among widows. It is the natural extension of Jesus Teaching in Luke’s Gospel.
and yet Paul; who is NOT the Lord; said:
1 Corinthians 7:13-14And if a woman has an unbelieving husband and he is willing to live with her, she must not divorce him. For the unbelieving husband is sanctified through his believing wife, and the unbelieving wife is sanctified through her believing husband. Otherwise your children would be unclean, but now they are holy.