Workflow timeouts are not related to activity timeouts in any way. So don’t change them for this use case.
You want to specify a long (the longest possible activity execution) StartToCloseTimeout. And then a short HeartbeatTimeout (let’s say 1 minute). If heartbeat timeout is specified the activity must heartbeat periodically with a heartbeat interval that is lower than the heartbeat timeout. This way an activity can execute for a long time and fail fast.
See this presentation that explains the activity timeouts in greater detail.