There’s no timeout for Suspended State. The only attention is about Queue if your long-workflow is use it
Best practices section of below link :
If a long-running workflow is attached to queue processing and the workflow is in a suspended state, the queue item will remain in an in-progress state even beyond 24 hours until the workflow sets the transaction status upon resumption. Queue item identifiers will be part of the persisted workflow context if included in the same scope of Wait and Resume activities.