I'd say its time to build a point to point link from the barn to your house.  I'd ditch the M2 and get two NanoBeam 5ac (Gen 2 if you can) radios and build the link between the barn and the house.  This will be a super fast link that will handle any speed increases you may have access to in the future.  It will also get you away from the 2.4ghz band which is crowded and noisy (interference).  In the house I'd use an AirGateway Pro.  It is a small access point/router that snaps into the POE injector of the NanoBeam and broadcasts 2.4mhz and 5ghz.  If you need additional switch ports you can plug a standard switch into the LAN port.

PS.....if you don't have great line of sight between the house and barn you'll need to stick with the M2 radios.