arkham-starter.com | The Scarlet Keys : Upscaled World Map
I took the playmat scan available at Hall of Arkham, add the Rome location banner that was missing, then enlarge with an AI Upscaler. But these kind of upscaler smear texts and symbols, so I cleaned up all the location labels manually and type back everything. Some other things are lost in the upscaling and I didn't manually restore them, for example blue star icon on the labels.
Using original output from the upscaler, image size is 8000 x 4516 px. Therefore if you are going to print them, at 300 DPI, this size can cover 26.67 x 15.05 inch or 677.3 x 382.4 mm. (Fits in A0 paper, 841 x 1189 mm) Download size is ~30 MB.
These are scaled further than the output from upscaler by 2 times, which blurs the background. But since I typed back all the texts before exporting it, you would still get benefit of sharp text at larger size. Maybe it is useful for even larger print. Download size is ~70 MB.