Crud. I just spent double that, almost.
Oh, well.
I posted as fast as I could. 
WRT54g plus a tupperware case:
http://www.2xlc.de/outdoor_wrt.html
He claims its been used in -20 C, which may not be cold enough but if you position it anywhere near the grill, you’ll be fine. Linksys doesnt rate it at this temp because they have no business reason to do so. Generally, solid state electronics love the cold.
Yeah, this is what was confusing me. Obviously electronics hate heat, but shouldn’t they perform well in the cold? Seems like it’s an ideal environment.
Yeah, I know, but I was thinking a device designed to be only a bridge might be smaller and cheaper (and it gives you more devices to check for cold resistance). I haven’t actually researched that, though.
Yeah, my concern was imagining a solder point that might be near something internal that got warm, and the delta between it and the very cold of the rest of the unit.
I’ll report back on progress, or possibly even make my new control device’s web page public the next time I’m cooking up a nice Boston butt.
Of course you know that since we helped you, you owe us some delicious barbecue, right?
I doubt it. The temperature deltas should all stay the same whether the environment is 100C or -40C.
The only thing I can think of is condensation. I can’t figure exactly how it’d be bad, but besides water I really don’t see what you’d be harming with cold temperature.
That, and perhaps a greater susceptibility to mechanical stress from materials become more brittle. But really, I can’t imagine what’s wrong with sub-freezing temps! Overclockers push those often.
EDIT: Wait, were the powerline adapters rated for sub-zero, but wifi gear is not?
No. A company in such a high tech area like the Bay area makes a device designed for outdoor use, needs a internet connection, but doesn’t have wireless built-in?
This is what is wrong with America.
Yup, the powerline adapters were rated to -4° F. I figure I can live with that.
Touche.
Damn liberals. 
I had a nice Boston butt once, but she didn’t stick around for the dessert.
Most equipment doesn’t list true low temps because its sold for indoor use. I’ve used lots of this stuff outdoors way beyond spec temps ( high and low ).
If you want good stuff made for outdoor wireless …
The ones i’ve used are rated -20C to 70C and some to as low as -40C , and most of it is under $100
Meflin
An update:
So there were some acquisition delays in some of the required hardware, but this Sunday I put three racks of ribs on the Big Green Egg, and set the Stoker to keep the temp at 190[sup]o[/sup]F. Then we went off to church, and a trip downtown, and some shopping afterwards. Gone about seven hours. I kept checking in on the ribs via my phone’s browser.
After a day’s low, slow cooking, they were fall-off-the-bone delicious. Absolutely awesome… and when I got home, the Egg was still at a rock-solid 190. I didn’t have to touch it once.
Next up: brisket.
Link, please.
So it sounds like you waited for fair weather to play with this. What did you use for internet to the egg?