Grill Block Attatchment?

[UfoTofU]

I am in the midst of doing a front grill block.

I have everything almost cut to shape but was wondering if caulking / glue will be enough to hold the coroplast in place? I was planning to use zip ties but looked at SVOBoy's write up ( http://crxmpg.com/grillblock.html ) and it looks like he just used hot glue to hold everything in place.

I live in Maine and winter is just about here and I was thinking that the cold might take it's toll on any adhesive that I might use. I was thinking that there must be an appropriate silicon caulk out there that remains pliable in hot as well as very cold weather.

Any one have any good suggestions?