You can buy long leads from PetEdge. Petsmart has them too but they are pricey! But, FYI the clip is HUGE. I prefer 3/8 webbing with the smaller clip, and I bought a 30ft long lead for training and the clip on it is a little big, like the clip on a 3/4 or 1" leash.
The alternative is a rope lead. That might have a smaller clip. Also, I have a puppy size tie out for Loki. Since we don't have a fence, I'll use it when we are out on the patio and he is outside with us. My neighbors use a tie-out for their dog when he goes outside, but I prefer the flexi for letting Loki out to pee. He needs to be supervised