You want, if possible, to retain the full original pixel dimensions. Always Avoid resizing if possible. This destoys the most resolution. It is better to compress than to downsize. At practical viewing distance, you won't generally be able to see the artifacts caused by compression in a 50 mb file that ends up 25mb file that was shrunk by increasing compression so that it fits in under 25mb. Sure, if you look at the print under a loupe you can spot some blocky pixels, but if you don't over compress, you won't see the usual JPG halo type artifacts we normally see at high compression. I've tested this on screen with a file that had to be compressed to quality 8 of 12. It still looked quite good, even at 100%. If you have detail that absolutely requires a larger file size, you need a custom printer to do the work for you anyway. Perhaps a Murals or Outdoor Advertising vendor. And you KNOW they just crank up the pixel size, and effectively increase the viewing distance more or less proportionally, in many cases. Photoshop and Lightroom have options that allow you to export images to force a JPG extraction to a specific targeted maximum file size.