an OG of 1.100 sounds like you added sugar to increase the ABV. a cider with substantial added sugar to achieve higher alcohol than a common cider is an applewine & should be entered in 28C & specify carbonation level (still, petillant, or sparkling) & sweetness (dry or medium)
if you didn't add a "substantial" amount of sugar, then it would be entered in the category it best fits; common, English, French or New England
if by "iced cider" you mean "freeze concentration" then it would entered in the category it best fits, just specify it's been iced.
I've entered my jacked applewine in non-BJCP competitions under 28C
"Why must it always be pandemonium?" - George Mueller/Nelson Van Alden
"Beer. Good." - Words of House Grog
drinking: Wojtkowiak Piwo, CLB's Barleywine, 8Hearted Pale Ale, O'Rob's Dry Irish Stout, DB8PT Session Ale, Wojtkowiak Grodziskie - bottle conditioning: Otto M. Gourd Pumpkin Barleywine, Jewel Thieves Apple Wine, CLB's Barleywine 1.2