Hey, at least you have a something along the way that 100 miles. Out here, I carry 70 mile range on a tour because it can be 70 miles to the next house, water, anything.
Starting point for you is just buy more battery. 50 mile range will do you most days. Slow riding makes your pack go twice as far, so ride 15-18 mph vs 20-25 mph.
Places I've charged. Overnight, at campgrounds where you can buy a space with a plug. Along the way, I've used hot plugs on businesses that are for sale and vacant, Community recreation centers, and city parks. But like I said, good frocking luck finding one in Las Cruces NM.

Look for RV folks. they have generators aboard, and are often friendly types.
But if all that fails, look for people, chat them up, and ask. Gas stations, coffee shops, dollar stores, whatever. Look for coke machines and Ice coolers. that means an outdoor plug.
Just start finding plugs in your area, and it will help you learn how to find plugs anywhere. If really desperate, as I was that one day at the vacant business, remember that vacant houses for sale also often still have the power turned on. Consider developing a network of peoples houses or businesses in your area where you have permanent permission to grab a charge.
I rarely use it, but in my town I have a few hot plugs located, and have a few friends sprinkled around where I can charge. In town, I'll never be totally stuck.
Lastly, because it is a dangerous ride for 50+ miles, consider getting a strong hitch mounted bike rack. Drive to coast or whatever, then go for a 50 mile ride. Because its 70 miles in any direction to nice forest from my house, I do this often. I don't always have the time or energy to ride there on the bike and back. Last weekend, I took a day trip and my wife and I had a nice ride around the forest through the last of the aspen trees in color. Sure, half a tank of gas totally wasted, but worth it.