What would you do? Surgery scenario

My baby will be 2 at the end of January. He has a surgery on the 8th of December in a city 3.5 hrs away. The surgery is for a mass in his neck, I’ll add a picture below just for reference. We have to stay at least 24 hrs because a draining tube will be left in his neck. Our insurance covered a hotel because we have to leave the 7th due to his surgery being early in the morning. We are estimated to be gone 3 days if everything goes as planned.

My issue is I told know what to do with our 3 year old. We want to take him and have someone come with us to stay in the hotel with him so he is at least near us and we would go see him of course. The other option is to leave him with my mom for those days but she doesn’t have a carseat for him and his carseat needs to be anchored in and I don’t think that’s an option in her car (it’s old). Would you take your other son or leave him in your hometown 3.5 hrs away?