Question about Netgear AirCard 810

I agree with the previous speakers. In America (at least in the bigger cities) there is free wifi in practically every restaurant, café, shopping mall, store. Otherwise, the device is great, but I can't say whether it is suitable for America or not.

I used this device on a trip to Russia and had good experiences with a map from Qynamic.
As Brimstone mentions, the available frequency ranges are unfortunately not very suitable for the USA.
However, I do not know of a device that is more suitable for this.

The supported frequencies for 4G are not used in America, according to my information. For 2 months, you can also just use your smartphone as a hotspot with a prepaid SIM card. Depending on when you are in a hotel every evening, there is usually also free WiFi there.