I would attend even if one parent didn't want me there. This issue came up a few years ago when my mother told one xJW sibling that she didn't want me and another sibling told if anything happended to her or dad. My sibling refused to go along with the request and said we had a right to know and besides, funerals are for the living not the dead.
I make sure that I can travel at short notice and have funds to get a flight if necessary AND assuming I am told in time. I hope it won't be for a long time...but you never know.
Thirdson