Adding up the maximum currents for the components for each state I got:

• Sleep: ~20uA
• GPS on: 34mA
• Tx: 45mA
• Rx: 15mA

On measurement things improve a little:

• Sleep: ~9uA
• GPS on: 35mA
• Tx: 33mA
• Rx: 14mA

Using a 400mAh battery, keeping the GPS off and sending one uplink every 15 minutes should give ~130 days of battery life on 80% of the battery charge.