Dale Hollow (troll bite)

Planning a spring crappie trip to Dale Hollow. Hope to troll. Long line, boards (if needed). Anyone have a general idea of timing on this trolling bite ? I'm sure early March it may begin ???? How long into April does it generally last before these fish move to shore ?
Be down for a long week. Thinking last week of March ? First week of April ??
Thanks in advance everyone ???

probaly already on the banks by then.

Thanks Dave. Thought those dates might be a little late. We may start eyballing more mid-March.