I've had a TP Link Archer C7 router AC1750 and modem router for years and used it with Comcast/Xfinity internet with no problems.  I am now contemplating ditching Xfinity and going back to AT&T for a cell phone that includes unlimited talk/text/data and a free Hotspot.  I've been researching if I can continue to use this setup as a connecting point to the hotspot so I don't have to reconfigure my wireless doorbell, HP LaserJet Pro MFP M477fnw printer and Lenovo Tab 8 tablet which are currently all connected on the same network.  All I have to do is turn each device on and it's automatically connected and ready to go.  I asked the rep at the AT&T store if I could do that and he said no, but there are YouTube videos that supposedly show how to connect with a hotspot. 

If my current devices will not do that, what about something like the TP-Link Network TL-WR802N?  I'm close to making the switch but want to make sure everything will be easily operable for me.