There’s two in the Vertebrate guidebook, I’ve done one, my wife has done both. The one I’ve done is essentially a loop of Whitbarrow: Gilpin Bridge – BW to Millside – BW & lane Witherslack Hall – BW to Halecat – tarmac lanes to north end of Whitbarrow and BW over to Lyth valley then tarmac lanes back to GB. We did that route one new year’s eve and it wasn’t boggy as the tracks are on limestone so they drain well.
The other one is Staveley then roads to Cartmel Fell and then various farm tracks above CF and in and around Simpson Ground. This one is a lot of road to link up all available tracks/BWs. Again reasonably weather proof.
I grew up very local to all these. A hardtail would almost be over-biked on many of them, if it was dry then a CX bike would be enough.