I'm sure you know the strain and difficulties associated with dialysis, once your G-FIL stops his treatment, I do not anticipate he will survive long.
Last June my father was hospitalized on a Thursday, my husband and I had long planned a trip that had us leaving on the following Tuesday for the Caribbean & we were traveling with another couple on their first trip. Of course we did not purchase an insurance/cancellation policy. We waited to see his out come.....Dad passed on Monday morning & we decided to take our trip with some creative added flights & hotel accommodations due to the fact I was located in a different city than our Caribbean travel departure city.
Now keep in mind this was a family decision to continue with the trip-we had been through quite an ordeal, and it would be a week or so before all the arrangements could be put together for a service, etc. It came down to "Dad would want you to go & have a good time instead of sitting here feeling sorry for yourself".
My suggestion is do what feels right for you and your family. The loss of a loved one is difficult. For my situation I waited until the last minute to cancel, if Dad did not pass on, before I was due to depart, I would have cancelled my trip to be there with him & my family....we were expecting his final rest. Because he did pass prior to my planned departure & the family need time to....just unwind, accept the loss, & complete arrangements, Mom, sis, & husband all agreed it would be ridiculous not to go. I was really concerned with "What will other people think of me????" But it was the right thing for ME, to do. My family members needed to have space & time to deal with the loss, I had been through days & nights at the hospital, I was worn out & taking my trip helped me deal with my own grief.
Being that this is your husbands GF, he should really make the decision if he feels the trip should be postponed, you should support either decision. I'm sure he knows the family dynamics well enough to make the "right" decision. I am not in the medical profession, I have lived through a life of dialysis (it affects the WHOLE family) & I do know a person will not live long without the treatment. I would wait to cancel (if you feel okay with continuing to travel if he does pass), but would also contact all your RSVP to find out what your options are.
Condolences.
Off topic: This trip to WDW for my sister, Dniece & Dnephew is for my father
He would be proud that I can give his grandchildren whom he loved SOOO much a little piece of Disney magic. How ironic.
