An easy way to work with two providers at home?

Question

network hardware

Greetings. Need a hint.
At home, the constant availability of the Internet is critical. I want to implement automatic or semi-automatic (turn on the second device as a last resort) switching to a backup provider if the main one definitely does not work. When it works, it would be nice to switch back automatically, but in extreme cases you can also manually.
Now there is a simple TP-Link router, it does not know how to 2 WAN. The main provider gives the Internet via IPoE, authorization seems to be simple via MAC. I’m still thinking about the second one, maybe MGTS GPON, Beeline or Online with a minimum tariff.
I'm afraid of double NAT for devices behind the main router, if you put the second router in front of the first. I actively use SIP at home.
It would also be very nice if, when the main channel fell, it would be possible to connect to the home network from the outside (rdp over vpn or ssh) through a backup provider if the first one is temporarily unavailable.
Once I had a Mikrotik and played with it. I would like something even simpler to set up.

Answer 1

Keenetic can assign wan to any switch port. Easily set up prioritized reservations.

Answer 2

Many Tp-Links are compatible with dd-wrt firmware capable of doing dual wan . Well, in vain you are so to Mikrotik, in vain in vain in vain ... =)