Is there enough virus to be dangerous though?
This is the bit I'm interested in! Whether fomites are a possible transmission risk now with the new strain.
Would you not wash your hands before you ate the sandwich?
I wash my hands, make my sandwich, and eat it, usually. I don't was them again before I eat?
But even if I did wash my hands immediately before picking up the sandwich - I'm being thick but can't see how that makes a difference?
My (washed) hands have opened the packet of cheese, taken out the cheese to cut it, so I've handled the packaging and then the cheese, then put it between the bread.
I guess you could handwash in the middle of the sandwich process after opening the packet before taking out the cheese? 
To me it's a lot more effort to do it that way, I feel it's easier to clean stuff and then they go in the fridge and I don't have to wonder if they're clean or not!