In the past I have used an Apple Airport Express for just this function. I suspect the full size Apple Airport routers can also be configured this way.

One nice thing about the Apple WiFi router devices is that you configure them using an app, not via a browser to an IP address. Once you get the hang of using the app, much quicker than futzing with IP addresses that disappear each time the thing reboots itself.

A similar device category is WISP, some of which also have an Ethernet port. I use a WISP device to share hotel WiFi (which is restricted to a single device IP) with multiple in-room devices. I think it can also link the on-board Ethernet port to the WiFi host.