Yes, depending on the type of policy you have. We would need to confirm that you have not, and do not intend to make a claim on your policy.
Annual Multi-Trip policies can be upgraded to a higher trip duration, based on your current trip duration and policy restrictions. We would ask you to check your Policy Certificate for your existing trip duration, and your Policy Wording for the maximum trip duration.
If you have a Single Trip policy, provided that you let us know before your policy expires, a Single Trip policy can be increased up to 365 days.