i'm in toronto as well and i got teins coils. However, this won't apply to you, but teins use stock struct tops for mounting so switching back and forth to stock shocks is out of the question. Then again, teins doesn't get slammed that low and my winter tire diameter is slightly larger than summer's, so my ride height is a bit higher during winter.
if you go back to stocks, your camber will be off and you'll be wasting your tires faster. One reason why people get coilovers is that they're height adjustable. If you find your car unable to clear the snow, you can raise your coils higher during winter. It'll give you an opportunity to check if your coils are seized or not, then apply whatever lubricant you need on a routine basis.
also, toronto's got pretty decent snow plowing service, i don't really see a need to switch back and forth. and it really is a hassle to switch considering you need to provide resistence on the brake assembly when you tighten the bolts (did the install myself, it's a pain to do all that). So unless you've got $ to burn or your friend does it for free, i personally don't recommend it cuz it's not worth the time/$.
i did smudge a whole bunch of syntheic grease on the threads when I installed my coils, eventhough i don't see myself adjusting them again. The only thing i may be concerned about with seizing is when i sell my car and want to take the coils off for resale... but that's probably 10 yrs down the line and by then these coils won't be worth much.
just my 2 cents.
also... toronto accord meet??!? lmao...