I was the same as you in the NE days bones.
I refused to have anything to do with the NEs or the NRL. I didn't watch it on TV, didn't buy merchandise and I certainly didn't go to games. My reasoning was that if everybody had the same attitude then our merger would never have happened because it simply would not have made commercial sense for anyone. Deep down I hoped my protest would lead to the reinstatement of Manly and, while my protest may not have been a big part of it, ultimately I was lucky enough to get my wish.
A lot of my feelings on that were driven by the raw deal we got from Super League and the way the mergers were exclusively forced on the ARL clubs.
If a relocation were to happen, I think the background events that led to it happening would be a big thing for me to consider before deciding whether to continue to support the club. However I think more likely than not I would just stop watching RL as it would never be the same. It would be a sad sad day and I hope it never happens.