Ownership is the exposure, not presence
If a guest is injured at your cabin while you are three hours away, the claim is against you as owner. Being absent neither helps nor is relevant. Everything about the condition of the property, the stairs, the deck, the water heater, remains yours.
Guests bring guests you never agreed to
Lending a property to a friend for a weekend frequently means people you have never met using it. Your liability extends to them, and you have no practical control over what happens or how many turn up.
Money turns it into something else entirely
Accepting payment, even informally to cover costs, can move the arrangement toward a rental and into business pursuits territory, which personal policies exclude. The distinction between lending and renting is money, and it matters more than the informality suggests.