I’m seconding SwingTheLamp@piefed.zip 's comment, but would begin with 1 step below that:

simply find the best location in the house for having a good ( not your ISP’s, unless it actually is a good MIMO router ) wifi-router, with no AP’s or any other radios, & see how that works, 1st.

IF there are areas that won’t work, THEN do the wire+AP thing, as required.

hth!

_ /\ _