I run Palladium Fantasy instead of Rifts, but it is still nice to have large encounter maps sometimes. Since the hex grid seems to act as an overlay to a square grid base, I set up all my maps on a square grid, and once I am done messing with them, then I convert to a hex grid at the very end. Here are the things I look for in a larger map: 1. The default square grid size is 70px. If the image is high enough quality, it can often be stretched double the normal size without looking too bad on Roll20. So, for a 50x50 grid map, I will need a 3500px square image. I might be able to get by with one down to 1750 though. If you can't find anything searching around the web, there are some map building sets on the Marketplace here that can be pieced together to be as large as you need. Most of them are downloadable to assemble them in GIMP or something to be one image if you want. 2. If I need a map that seems larger than the one I have, then once I have my map stretched out, and the grid set to hex, then I go back in and set cell width to .5. This doubles the hex count on the map. This looks best in my experience if you are using the compact token bars. This is because the numbers in the regular bars have half as much room to display, so they mostly get cut off. At that point, you pretty much have a 100x100 grid map. Scale up as needed, though it can get laggy for some people if you are also using dynamic lighting on a large map. Now that I think about it, there is another thing that should be mentioned: always set tokens up on a map with the default cell width of 1. If you do that, the tokens should automatically scale to the grid size of any map they are dropped on. If you don't set them up on a default grid, often the tokens don't scale correctly to any map grid other than the one they were set up on. Hopefully something in that rambling can be of use. Good luck with your maps.
