Assuming wood frame construction of main structure. Challenges: fire already past egress point at patio doors of main structure. Exposure of propane tank in backyard. Possible hazardous storage in garage. Garage may be block construction.
1st attack line (1 1/2) would be in main structure towards opposite end of house from fire (to push fire back towards spent fuel. 2nd line would be 1 1/2 inch line deployed to attack garage from rear outside and provide exposure protection to propane tank.
Size up would be working residence fire fully involved with detached garage involved. Request 2nd engine if not already dispatched for water supply.
(Let’s see if I’ve forgotten all I learned from 1977-89.
One other thing that I would like to add is the house sits off of the road a pretty good ways. Laying line will be needed but depending where you are, water supply might be an issue too. If this is the case in your jurisdiction, plan for water supply needs. Also, with fire already in the attic and moving, I would probably choose a second line of a 2 1/2″ line. I like to go bigger with the second line when I’ve got a lot of fire showing at the get go. This works well to back up the first line in case it isn’t enough initially, the bigger second line is already deployed and ready to go to work.
Have great week and stay safe.