We've had threads on bicycles before. Like any vehicle it depends on your needs and your terrain. Folding bicycles are popular with the military because they need to store and transport many of them at once or strap them on paratroopers but for a normal person they're pointless. More parts that can break, more expensive and they generally have smaller wheels. If you really wanted to you could put quick release skewers on the wheels of a normal bike to make it easier to transport on or in a vehicle.
And kits for turning a typical bike into a moped are much cheaper than those for an electric bicycle. While they're much more noisy it's easier to make or find fuel for in a SHTF scenario than recharging a battery. They also have much longer range and power.
Best advice I've seen on /n/ and elsewhere is go to a local bike shop and buy an older used steel frame model that's fitted for your size. If you expect to use it wearing boots make sure you have those on when trying it out.
A decent rear cargo rack should easily take almost any sized pack. Just remember to keep a few bungee cords on it at all times.