I created a pre-mist map (as a sort of fog of war layer) for my players - based on the memory of the elf character in the party.
As they explore I reveal more and more of the real map.
I used Wonderdraft, free assets from 2 minute tabletop, and some final editing in Photoshop using a custom "medieval crop/fields" brush.
I loaded a hi def version into Roll20 and used the hex grid system they have in there and sized everything up and it works great.
Here are pics of the maps and a roll20 screenshot:
https://imgur.com/a/R5ufXiL