Sorry if too long...

I want to power on and off a Hotspot in my RV to a set schedule. So, given that this is an RV it will be without power for up to 5-6 hours on occasions while we move locations. 

How long with the device "remember" it's set schedule?

Must it have a wifi connection to operate that schedule or will it function without that connection?

If this model won't do this, is there one that will?

thanks