Read most of it and honestly I can understand in a way. You sound like me, being organised and planning well in advance, being ahead of yourself. your DH more laid back like mine. Your DH is also grieving.
Last year I lost my granny six months before christmas. If it wasnt for the kids, I wouldn't have celebrated it at all.
The red cabbage probably brought back memories, again I understand this as I inherited my old teddy bear from granny's house, it smelt of the playroom. That was one of the hardest bits of the process, the smell and memeories hit you when you least expect it.
Yet grieving people are also the most irrational. It sounds to me that he may be expecting you to know hes hurting and why, yet doesnt manage to articulate that well.
I do understand your need to be organised, as I am the same, however I have come to admit recently that what I see as organised, others see it as micro managing and yes sometimes controlling. And that's rubs people up the wrong way, and it is something I'm working on.
Equally it sounds like your DH is like mine, and that is so laid back he may be horizontal. Again hes also grieving. He might have thought he was ready, then found out on the day he wasnt; the thing about his sister just seems an inconsequential thing, but often in grief it's the unimportant things you latch on to to express the hurt, as the real things are too big and hurtful to deal with.
These are two polar opposites, and I think the best way you can go forward from here is both of you compromise how to deal with things, and find a middle ground; also you listening to what he is trying, and failing, to tell you in that he is hurting and wants you to notice, without using so many words, but by the same token he has to stop using you as an emotional punch bag for his grief, telling you to do one thing then getting arsy when you do it.
Both of you, and I say this with no judgment what so ever, need to really talk, and listen to the other.
I would encourage him to see the GP for grief counselling. My DH had it after his mum died 16 years ago and it helped.
Wish you both all the best of luck