5mi/8km round trip? I would buy a beater bike at a yard sale, lock it with a lightweight cable, and keep the good hardware at home for fun rides. This is what I have done for almost 35 years, and the only bikes I have ever lost to theft were a Sears Free Spirit and a low-end SR 10-speed, both of which were $15 yard sale treasures(?). For a short commute, it is almost as much fun to ride a junker with a lightweight cable lock as a nice bike weighted down with 4 kg of security devices. (In the 1970s, I carried a big case-hardened chain and an Abus Diskus padlock, and we used to joke that "the lighter the bike, the heavier the security system.")