I usually have 2-3, 1 lb nonrefillable bottles in an outside compartment that does not have venting. I can't say I've worried about them too much. I disconnect the tank after using the tabletop grill. In stores, it is typical to have stacks/pallets full of 1 lb bottles in the middle of the store while the refillable types are outside the store. I do have a LP detector in my TC.
My camper has two refillable bottles in an outside sliding compartment. I can't imagine ever using both tanks in one trip since two tanks typically lasts a season. The only exception would be if I was boondocking for a long period with no access to electricity to run my electric heater that has multiple settings.