I think you probably mean a Gunnera, and they do grow very large, so if you really want to grow it in a pot, the pot will have to be huge!

Frankly you can't grow an Gunnera in a pot it needs to be in deep moist soil... Sorry Thawkins and welcome to GoY.

These can can get very big and if you have a very large pond area then these look fantastic, once established they have to to be reduced by hacking back the large crowns, in a small pond setting they are just to big, create a bog area near to the pond for best results.

As said previously this is an outdoor plant. Your location is from Oregon, USA. If you have a place for this large plant outdoors check your growing zone for this plant. Even though your plant would be heavily protected in the winter, your state local growing zone where you reside may render its survival unsustainable.

There are lots of varieties of gunnera that are small and hardy: hamiltonii, magellanica, prorepens. Manicata and tinctoria are the larger sized gunnera and both are relatively hardy...if they survive the UK then they will do fine in Oregon.

Loosestrife2 is correct--parts of Oregon can get winter lows below -20º (-29º C). Coastal Oregon is likely to be fine, but the Cascade Mountains are too cold, and the eastern half of the state is likely to be both too cold in the winter, and too hot and dry in the summer.