My rule of thumb is the smallest (QRP) rigs need the BIGGEST antennas. Just to make it fair.
That halfwave of wire thrown up into the tall tree is an idea that I had when I started taking a QRP rig camping.
No feedline to carry, no ground counterpoise required and the results usually are good just using a small tuner to match the high Z to the radio..
A small NiCd battery and some kind of charger, my old J-38 key, a few hand tools, tape measure (for tuning) and a notebook and pencils for logging completes the kit.
Have Fun !
73.....JD, FISTS #3853,cc 455,SKCC # 1395,tribune #12,
Official US Taxpayer