Setup recommendations?

Hi all,

currently a Netgear R6300v2 running dd-wrt provides wifi access/routing in my apartment. The apartment is across 2 floors in the tropics and no AC. The router needs to be in a place with little ventilation and I see it running CPU temperatures between 84-90C and radio temperatures between 55-60C. Wifi coverage in the upper floor (router is on lower floor) has always been noticeably worse than on the lower floor. In recent weeks, the wifi connectivity has worsened considerably and I assume it’s due to wear worsened by heat. Very likely the router will need to be replaced soon. What I am looking for:

  • able to support ISP speed 50MBit/5MBit
  • very low heat generation/power consumption under load
  • coverage across 2 floors in apartment building made of reinforced concrete
  • support for 4-5 devices simultaneously (we have about 10-12 devices in our household)

I would be willing to mesh 2 units for the 2 floors if that would be the best option.

I would very much appreciate recommendations.