The Sespe River Trail would be a great trip. The main trail follows an old dirt road (now trail) along the Sespe River. Parts of it get a little brushy and hard to follow as you get more than ~11 miles in, but with some diligence and basic route finding skills, you should be okay. There's lots of great swimming holes along the hike and two areas with natural hot springs (Willetts [~11 miles in from Piedra Blanca TH] and Sespe Hot Springs [~15 miles in from PB TH]). The Sespe Hot Springs are the hottest in southern CA, I think, and probably woudln't be very crowded this time of year since the other two ways in are hampered with seasonal road closures right now (I think).
There are a few other really great trails in the Sespe that you could combine with a Sespe River Trail hike or do instead such as the Alder Creek trail (from Dough Flat), Red Reef Trail and the Gene Marshall/Piedra Blance trail.
This last one might be a good hike for you... it has a Sierra feel to it and can have some snow during the winter, but shouldn't right now since we haven't had any measurable precip in a while. You can leave from the Piedra Blanca trailhead and head north on it, up and over Pine Mtn, or you can start from Reyes Creeek Bar & Grill off Lockwood Valley Rd from Hwy 33 and head south, up and over Pine Mtn. There's some neat areas up around Pine Mtn/Reyes Peak worth exploring too- like the Fishbowls, Cedar Creek, etc.
A good map for the area is Tom Harrison's Sespe Wilderness map.
PM me if you need more info. Also check out the Condor Trail on Facebook... lots of good info/photos/knowledgable LPNF folks loitering on there.