What changes the answer?
The gas utility's investigation addresses the suspected gas hazard. A furnace service evaluation needs to address how this particular appliance burns fuel and vents its exhaust. Those questions overlap, but they are not interchangeable. Ask what was checked and whether any appliance work remains.
Cold weather can affect vents and gas equipment. Xcel Energy warns that snow or ice can block appliance exhaust openings and create a carbon monoxide hazard. That is a reason for the qualified evaluator to consider the weather conditions, not proof that snow caused this odor. Xcel winter vent guidance.
After the site is cleared, share the approximate outdoor temperature, whether the smell occurs at startup or during a whole heat cycle, and any photos you already have of the vent location. Do not put your face near the outlet, intentionally run the furnace for a smell test, or climb onto a roof to inspect a vent.
What should the explanation include?
Ask the technician whether the installed vent arrangement matches the model's instructions, whether a blockage or exhaust problem was found, and whether combustion testing is needed. Request the finding and the basis for any repair. If one person says the utility found no leak, ask whether that also included the furnace operating question you raised.
The next step is two clear answers: what the emergency check established, and whether the furnace needs further work before use. Cold weather is context for the assessment. It is not a safety clearance.