Such long cables increase the risk of electromagnetic interference; I would just deal with it with RC filtering (the capacitors I mentioned in my previous post).
Like 4.7kOhm pull-up first, after the pull-up a 1kOhm series resistor, then a 100nF capacitor to ground.
"Filtering the shit out of it" works because with mechanical switches, you don't need quick response. A 1kOhm + 100nF filter has approximately the response time of R * C = 1k * 100n seconds = 100 microseconds.
Others may recommend heavier solutions. One of them is optoisolation. Optoisolation gives some robustness against EMI for two reasons not related to the isolation itself:
1) They are SLOOW
2) The LED requires quite some actual current to drive. A small inducted current cannot make it light.
Isolation is nice, but note that you need a power supply so that current can flow through the switches, to the LEDs in the optoisolators. And to keep the sides isolated, this power supply needs to be isolated. Cheapish isolated DC/DC modules exist for this reason.