Excellent info, thank you.

I still think with laptops that have 2 RAM sticks under the bottom cover and the other 2 sticks underneath the keyboard, the spray can attack would be trickier. I assume though it's possible the attacker can keep the laptop running while the palmrest and keyboard are being disassembled. If the attacker cannot freeze all sticks of RAM though, would the attack be less likely to be successful? Would the disk encryption key be spread across all RAM sticks, or possibly just one?

I will look more into the hardware memory encryption as suggested.