Custom exposed filter to select expired nodes
What about running a cron task that sets the status of offers to  unpublished once the expiry date has passed.

Then the view can simply filter on whether or not the node is published.

If you don't want to go down that route then alternatively create a filter based on date and then with a little jQuery hide that and add some radios. Then when the radio is changed set the date filter to the appropriate value and submit the form.