Install as an app: on the hosted site, Chrome and Edge show an Install app button (or the install icon in the address bar); in Safari on a Mac use File > Add to Dock. The installed app opens in its own window and still loads with poor or no signal. Maps and terrain not already downloaded need a connection.
This is a planning estimate based on bare-earth terrain. Buildings and trees are approximated by the clutter setting. Always confirm critical areas with a field test.