I think they can still reach 109 from 113 via 110 thanks to the W German naval base, but the northern route would only get them as far as 119. So I guess 112 would be the better place for the 5 subs.
Now if UK attacks 112, could they prevent Germany using those subs to soak up hits by attacking with fighters and remaining navy EXCEPT the destroyer(s)? I think subs cannot be hit by air units unless an enemy destroyer is present, but please correct me if I am wrong on that.
Similarly, if UK chooses not to attack 112 but wants to protect 109 with its remaining fleet, then maybe they would not want a destroyer in 109? Destroyers in 119 and 110 could block Germany’s surface ships, so taking out the battleship or whatever UK has in 109 could be costly to the luftwaffe? Would it be worth it for UK to maybe buy a new destroyer for 110 and make Germany lose air units?