Wake on LAN is pretty reliable if you're inside the network, so doing it from the sofa etc, the most I find is you sometimes have to fiddle with the power off state in the BIOS to ensure it keeps network card active. It's much more of a challenge from outside when travelling though as it's normally the routers which kill WOL packets. Not many of them support broadcasting something hitting the public side across the LAN, making getting the signal from outside into the network difficult. In that situation, I'd agree with either having a smart plug and ensuring the bios is set to auto boot on power on. Or have something smaller and low powered sitting permanently inside the network (eg mini PC, Raspberry Pi) which you can piggyback onto and use to still send a local WOL packet within the network to start the bigger machine.