After my last activation where I accidentally left behind the 40 m dipole wires, decided to change to a linked dipole. That way guaranteed to have all bands in my pack :)
These a quite commonly used now in SOTA activations. Fairly easy to make. Got a small cheap ruler from an office supply store, cut it in half for 2 and drilled some holes for the wires. Threaded the wires for 20 and 40 m antennas through and soldered on alligator clips.
Now to operate on 40 m leave the clips in place, for 20 m drop the squid pole and unclip.
Initial testing on the squid pole in the driveway show SWR not too bad on both bands, both a bit long, so will need to adjust. Then try out in the field.