Picnic. Wine. Temperature.

oh, what lovely weather we have today! i know, we'll have a picnic! oh, but naturally we must bring wine, we just must!

losing half your sparkling wine because it's way too hot is no fun. neither is having your supposedly ultra-crisp and refreshing white or rosé be flabby and heavy due to the heat. this we all know. coolers are big and clunky, and unless going with your personal automobile, utterly impractical.

but now here's something that occured to me. chill your desired bottle to slightly below optimal serving temperature, pop it open, and, here it comes, are you ready? pour it in a pre-chilled vacuum flask (thermos).

for still wine i believe it would work perfectly, but would a thermos be able to withstand the pressure of a sparkling one?

any thoughts, or better yet, experience regarding this?

hmmm... This sounds like a job for a clever inventor. I think a themos type container designed to hold an entire bottle with a freezer pack inside. As soon as the rush is over, I'll put on my thinking cap.
EDIT: Just found this: http://www.amazon.com/Thermos-Epicurean-2-Bottle-Wine-Cooler/dp/B00AJH03QK

I find a icepack sleeve works well (except for things like Taittinger Comtes or Special Club Champagnes, too fat).
With a careful decant a thermos would probably retain some effervesence.
Don't think once poured there would be enough pressure to cause any problems with thermos/.