Is this your first electric car? I ask because EV enthusiasts refer to that gauge as the "guess-o-meter." It anticipates how many miles you can drive based on past experience but has no way to accurately predict what you're GOING to get.
Range depends on a lot of factors, including temperature, use of a/c or heater, driving style, if you're going uphill or downhill, and probably some other factors I'm forgetting. I once had my guess-o-meter (on my Nissan LEAF, all-electric EV) tell me that I could go only 18 more miles, and I was 25 miles from home. I drove a couple of miles and the GOM read "20 miles" of range left. I drove a couple more miles and it said I had 22 miles of range. Somehow I was GAINING range the farther I drove. I finally realized that I was going from an elevation of about 700 feet to about sea level and was coasting downhill much of the time, recharging the battery and altering the guess on my range. I got home with about 12 miles of range left on the GOM.
So, anyway, don't take that range thing too seriously.