@camcleo 

Any of the range extenders should work fine. TP Link has a lot of them. Pick one the works best for you. I would pick one of the upper models so you have more features although you may not need them now.
 

Important to put the range extender in a spot where it gets a good signal to both the router and to the area you need covered. 

  @ArcherC8 Hi,  Could you give some specifics?  There are pages of extenders and I don't have tech knowledge to really hone in on a product.  Should I look for an outdoor extender or could I use an indoor extender to extend the range 350 ft to a garden outside my house.  I would prefer indoor placement if that is possible.  Thanks for your help.

  @camcleo 

If you can run an Ethernet cable to the Extender. get one that allows connection via Ethernet and placement is in your problem area. 

For WIFI extenders, placement of the extender is important so if you have a good inside place about half way between the router and the problem area that is protected, use an inside extender. 

If you have high speed internet or plan to in the future, a lot of devices that will attach to the extender, or just want future proof your purchase, get one of the higher models if the budget allows. One that is TRI band, AP mode, with high speeds, maybe MESH mode,...

I have used a RE220 to cover my garage which most use is WIFI cameras and my speed was only 400. It filled my needs.  The newer Extenders have more options and are faster than when I got mine. 

Moving routers and extenders can make a big difference in coverage area. Moving my router a few feet helped my overall WIFI coverage.