Update:

I found a company which does custom jig-saw puzzles up to 1000 pieces.

https://piecetimepuzzles.com/
They are not taking new orders now.
They are severely backlogged after being featured on CBS’ Sunday morning news show.

I am going to just wait until they start taking orders again and buy a custom puzzle commemorating the heroes in the fight against Covid-19.

I don’t know when that will be, but you’ll know soon after I do.
And, at no extra cost, here are a couple of photos of my current landscaping achievements.