Yes these silicone collapsible water bottles are freezable, however we would advise that the best way to maintain the integrity of the collapsible water bottles cap and bottle is to not fill the bottle to the top(leave about 1-2 inches) and to freeze standing up with the collapsible water bottles left open without the cap screwed in. During freezing and thawing there are expanding and contracting forces, with time these can affect the cap especially so therefore the best practice is to freeze without the cap and not filled up to the top.
Once frozen, simply add a little water to the top to begin the thawing process and screw in the cap.