The Rijksmuseum will let you order prints on canvas for what seems like a reasonable price to me: https://www.rijksmuseum.nl/en/rijksstudio/works-of-art/still... If you hover the 'Scissors' icon in the lower right while viewing a work of art, you can choose 'Order' and then you have some choices of crop, orientation, poster or canvas etc.

Unfortunately you need an account to see pricing. It is cool that they eventually will be able to serve US customers (currently EU only).

I see prices without needing an account.

I've used Shutterfly to order canvas prints. It's still ink and not oil paints, but it is on canvas. The result isn't glossy like a photo print, but it also doesn't show brushstrokes like a real oil painting, although I guess you would still see some if you sent a picture of an oil painting. They love sending out coupons that make it reasonably affordable. The canvas comes mounted on an internal wooden frame.

You'll probably get copyright questions if you submit an professional artwork, but if you can show it is in the public domain they might do it. I've never tried.

I’d be very interested in this too. The museum should set up a service and take a share of the profits

They did, you can do this from the page viewing the artwork itself, put onto a poster, canvas, aluminium, or a gallery print.