Most modern cars will be absolutely fine if left for a five-week period, although it would make sense to ensure the battery remains sufficiently charged. You can get a solar-operated battery conditioner that plugs into your 12v socket, or a trickle charger if you have access to a power point. If you don't have either, perhaps you can ask a neighbour to periodically start the car for you and run it up to temperature while you are away? We do not anticipate there being any long-term risk in not using the vehicle for five weeks. When you return to the car and drive it for the first time, brake gently for the first few applications to clean off any residual surface rust from the brake discs.