This question is unanswerable - depends on the undefined IR remote receiver.
Pin 5 (BCM 3) is just another input (by default) but is probably a poor choice, as it has a 1.8kΩ pullup, and the receiver may not be able to pull it down.
Pin 5 can be used to reboot the Pi (but AFAIK should not affect the Pi unless shutdown - but I have never tested this)
Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
is configured as an input key that generates KEY_POWER events.
This event is handled by systemd-logind by initiating a
shutdown. Systemd versions older than 225 need an udev rule
enable listening to the input device:
ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
This overlay only handles shutdown. After shutdown, the system
can be powered up again by driving GPIO3 low. The default
configuration uses GPIO3 with a pullup, so if you connect a
button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
you get a shutdown and power-up button.
Params: gpio_pin GPIO pin to trigger on (default 3)
active_low When this is 1 (active low), a falling
edge generates a key down event and a
rising edge generates a key up event.
When this is 0 (active high), this is
reversed. The default is 1 (active low).
gpio_pull Desired pull-up/down state (off, down, up)
Default is "up".
Note that the default pin (GPIO3) has an
EDIT To clarify you do not need
gpio-shutdown to get powered up by driving GPIO3 low. This is always active UNLESS you use