Usually there will be a retry mechanism from the Stripe end. Meaning if the webhook req is failed. The service will retry the same request after some interval.
As @mcnaveen Said there is usually a retry on the other end, but of course that doesn’t solve everything. For example if you webhook is offline too long the retry will not keep on trying for ever.
You can use a service like hookdeck to catch all webhooks and send them to your n8n instance. This way you can always retry from hookdeck if something went wrong on your n8n webhook and it is offline for some time.
Of course you can also beef up your own server infra with webhook workers and loadbalancers, but that is often a bit overkill.