I'm not sure the federations use local testers. It's at least rumoured that Michael Rasmussen said he was in Mexico because he knew they'd be less likely to travel there than Italy. Also isn't there something about it being only the riders national federation that has the right to test or something?
The fact that the taken sample would also be stuck in traffic (as someone above suggested) shouldn't be too big a problem. I guess the result would just be in a little later.
In the end I don't think dopers see this as a chance to go overboard. As I understand it they are on specific programs in the first place, which they have to follow, so it wouldn't make too much sense, would it?
The problem might more likely be getting hold of the stuff at the moment! Hell, maybe the prices are on the up right now because of it, just like with hotel rooms...