Hi Poppy. So sorry for you all. I have to say that I agree with Debbie - you really have to play it by ear, and take one step at a time. I felt that my role was to facilitate my husband's journey towards decision making re end of life.
I was fortunate that he wasn't in denial about his circumstances, but he still had to go at his own pace, and there were issues he found almost impossible to address. Our GP and Macmillan Nurse urged him to think about end of life care and funeral wishes, but it took time (he died 5.5 months after diagnosis). I helped by doing background research into possible readings, music, etc. I kept the information I had gathered to hand , and whenever we had a moment when the subject
arose, I was able to say things like "I found this poem/whatever, what do you think about it?".
For various reasons it was really important for me that he updated his will. He kept putting it off, not because it was particularly difficult, but possibly because it seemed so final to him. It was eventually sorted - but only 2 weeks before he died. Funnily enough, we both felt such relief when it was done, and I wished he had avoided the stress by doing it earlier. But you can't force things.......
As you say, you are in limbo, which is such an unsettling place to be. Very best wishes to you all.