Delete pending offline/check payment baskets after x days

We have a subscription option that allows offline/check payments.

We have some users who abandon their subscriptions (never pay the subscription).via offline process.

We would like to create an Auto Action that would automatically delete any pending Payment Baskets that have a specific Gateway account and whose Initiated on date is 60 days ago.

Can you tell me IF this is possible with Auto Actions, and if so, what the trigger, conditions, and Action would be?

There's no trigger for that. You'd need to use CRON with probably a Query action and triggers set to None. The CRON would target the auto actions URL. You'd then need to put all those checks in a custom SQL to delete those baskets and any other data attached to the basket directly in the database. Probably easier to just filter CBSubs > Baskets once every 6 months to a year and clear them manually. Baskets won't expire if in a Pending state; maybe a feature to consider in a future release (e.g. expire baskets pending for 3 months).