1 you did not inoculate so you are probably safe, if you had inoculated the bacteria are inactive under 15C therefore when it warms up bottles could explode
2 meta and hot water is an either or choice. in a factory with new glass bottles we just use hot water, if reusing bottles I might put the chemical in
I've bought new bottles. They look kinda delicate so i'm kinda afraid they might explode during corking or boiling for sanitization. I'll keep you updated.
Also regarding cork sanitization with sodium metabisulfite, wouldn't the taste of sodium get into the wine if i keep the wine bottle horizontally? I would love to know your opinion regarding this
Edit: in case i want to use K-meta for bottles? do i need to fill them up with k-meta or just a little amount + shaking is enough?