If you’re comfortable navigating on the fells if the weather turns, good combinations of techie and duration in the North Lakes are:
– Seathwaite, Langstrath, Stake Pass, Angle Tarn, Esk Hause, Styhead, Stockley Bridge. (Shorter initial carry if you swap Langstrath for Grains Gill).
– Honister, Brandreth, Green Gable, Great Gable (or Windy Gap and down Aaron Slack), Styhead, Stockley Bridge.
– Honister, Dale Head, Dale Head Tarn, Rigg Head Quarry, Castle Crag, Grange.
– Stoneycroft, Sale, Crag Hill, Coledale Hause, Force Crag Mine (good in reverse too). Or a full horseshoe, ending with Grizedale Pike, or reversed to end with either Stoneycroft or Causey Pike.
– Helvellyn, Birkside, Wythop.
There are plenty of short techie descents dotted around (like Fleetwith to Warnscale mentioned above) but they’re trickier to join up. As also mentioned: most of this stuff is best tackled later in the day to avoid the crowds (it’s extra busy on the fells at the moment). With the days getting shorter, some routes are difficult to navigate in the dark if they’re new to you.