"Successfully manipulating a poll which employs this method would require following efforts and resources:
Gaining control over a large number of devices in the target geographic region for submitting votes through those devices"
So yes, it seems like it can be defeated via a remote desktop (or any proxy in the allowed area)
You just need _one_ device in the region, which can connect to the VPN or proxy service you were already using (the assumption seems to be that the attacker has a large number of IPs they can access through such a service). That device will get some added latency from going through the VPN/proxy, but because it’s physically close, the added latency will be small, probably not enough to reliably detect.
Does AWS Lambda count as a machine for these purposes? If so, you can get a nearly infinite number of them just by cycling a config param and casting another vote.