Without knowing what you're going for exactly, the large overworld map in Super Mario Bros 3 can be a good inspiration for how the player can quickly transport between sections. Early Zelda games also have good ways to, basically, teleport around the map, which you'll probably need as the scale gets bigger to stop the player constantly trundling through the same sections.
Saying that, I'd always try to make sure the screens are interesting and do a lot of work. Better to have 4 screens that are always evolving (based on character triggers, time of day/ seasonal cycles, items/ money that can open up different sections, NPC activity etc. etc.) than 100 screens of boredom. Again, the early Zelda games are a real masterclass in how to do this well.