Battery: How long does it last? (If it just sits in the parking lot)

[HBSRA10]

Folks,

Due to a family emergency, I need to leave town immediately -- that means I will leave my car in the office garage for 5 weeks. I do not have time to get a trickle charger, nor do I think I can find a place to plug it in in the garage complex.

In your experience, will I definitely have a dead battery when I come back? I will have a Motorist Assistance, so I can get help on jump starting if the battery dies. How bad/damaging would that be in the long run? In general, what do you recommend? If I can find someone to just start the car every 2 weeks would that be enough? How long can the car last without starting?

Many thanks for your helpful answers.