Caching feed items to mitigate feed errors and increase page speed

Thanks for the great plugin, so far it is working great for my purpose. I just have an issue with feed errors I need help with.

The RSS feed I am importing occasionally goes down, which results in a feed error on the front end. Is there a simple way to store/cache the feed (while specifying an expiry time) and ensuring that it only refreshes when there is no error, otherwise it just keeps the items from the last successful update?

I’m hoping this will have the effect of speeding up the page’s loading time and preventing users from seeing an error when the feed goes down.

http://wordpress.org/extend/plugins/rss-import/