All answers are an Island on or around the UK. All clues are cryptic, and no number of letters is given.
1. Then at a stroke we found it was in Devon
2. All huff anf puff in search of a small western isle (not Lundy that is another answer)
3. Consider long and hard before making your decision
4. Firm land in Somerset marshes made famous by a cake-burning king
5. Although up north a trip around the tube should make this one clear
I've managed to sort the remaining 20, but these have really stymied me. Any help will be greatly appreciated.