Wp google map have a functionality to use the Screen-specific settings when you’re nearing the end of active development and want to perfect how your site looks like on specific mobiles (e.g. a certain ipads or smartphones) and insert width, height and zoom level according to specific screen size.
Display map according to specific screen size
Step 1 Go to Add or Manage Map Page.
Step 2 Scroll down page and navigate to ‘Screens Specific Setting’ section.
Step 3 Then enter width, height and zoom level for different devices.
Step 4 Click save map and view in different devices.