I can second the recommedation for using powerline ethernet adapters. I have one running from my modem to an adapter plugged into a wall socket. I have 5 streamers of various brands scattered about my house (including the garage) - each plugged into an adpater in a wall socket (even one plugged into a powerstrip). They all stream perfectly with no drops or lags in signal.
Another poster mentioned TP Link. They are great and so are others. I've learned that you don't have to use the same brand. I use a mix of TP Link, Netgear and Tenda.
Audiophile purists will likely say sumthin about noise from all the other things using electricity on your circuit. Maybe my ears are defective bcuz everyting sounds just fine to me.