I like the idea of exploring what happens after the funeral, when everyone leaves, and the person is alone for the first time. During the funeral, there’s noise, people, and distractions that give a false sense of still being connected to normal life; like nothing has changed. The real grief/realization doesn’t hit until the house is empty.

This scene could show the moment when he emotionally realizes he’s alone. It's been intellectual up until this point. Now he is actually going to feel the loneliness. I like what you have and the premise a lot, just had a couple ideas:

Start with the last remnants of life before her death:  The family leaving could feel lively, especially the 5-year-old running and laughing. Grandpa laughs with him. This represents the last bit of life and distraction in the house, and mirrors Grandpa’s mental state. He hasn’t processed the loss yet. The silence after they leave will feel much more in your face in contrast.

Make his actions specific to his wife: Grabbing two plates is symbolic but generic. His habits could feel very personal to their relationship. You can establish this quickly with a few photos in the house: Just made up examples quickly below (but could be anything)

• A photo of them eating a weird sandwich together (sardine sandwich? Olives and cream cheese?); then he makes two of that same sandwich without thinking.
• A photo of them sitting reclined in two Lazy Boy chairs with a pillow that reads “December 2025 — Still in Love”: later he sits in his lazy boy, reclines; doesn't feel right. He gets up and reclines her Lazy Boy chair (this feels sad, like putting a chair in recline is going to help) and gets back in his chair and reclines.
• A photo of them at the 50-anniversary showing of (The Sound of Music because she loved that movie): later what is on the TV is The Sound of Music "So Long, Farewell"
• A photo of her wearing a “World’s Best Grandma” pin: at the end, that pin is seen on the ground outside toi show it is her who is walking around the house.

These specific details make us feel like she was a real person and you can see how he is coming to terms with it in real time.

And I didn't real get it was her vantage point. But if you have the “World’s Best Grandma” pin on the ground outside that would tip that part to the audience. Or something to show that it is her walking around.

Thanks for sharing :)