I’ve updated the beta version of WordPress Google Form v0.46 yet again to beta-7 and made it available for download from this site. This beta update adds a new settings on the plugin settings page to control the timout value for the WordPress HTTP API. Increasing the timeout appears to help with very large Google Spreadsheets.
Download the beta release and please let me know if you run into any issues.
Google Forms Beta (40579 downloads )