if i had 5 devices that needed to use my I2C i could use some these ICs and wire all them up and allow one at a time to use the bus,
No that wouldn't work because the I2C data line is bi-directional and these latches are not.
but how much can it store and for how long,
1 Bit for as long as power is applied
is it voltaile?
but then again i keep thinking this is all possible through code...right?
No, no amount of code can reduce signal line impedance.
i mean if you have 5 sensors all sharing one data bus, you obviously can only read from one at a time, so you just control which one is on at a certain to then turn it off and then turn on the next one
No because when a sensor has no power it's output looks like a diode thus shorting out the sensor that is turned on.
with some real world applications where they are absolutely needed and cannot be worked around
Memory and I/O using several chips on a bus system.