I think the whole Lydia thing had two angles. To keep Jesse free, and to facilitate Walts return.
You don’t know that he is dead, you only know he’s shot and on the floor.
If you watched Talking Bad last night, the kid that plays Walt Jr. Seemed to tip a hand, when he talked about his character getting the 9 million.
Walt, further co-opted his former partners that stole his work and formed the company they excluded him from, that would serve as a substitute for Madrigal. Secondarily, Given his concern for Jesse and his family, walking away from the remaining 80 million, is nonsensical.
Watching that episode made me think the “end” was a marketing device.
If the remaining money was in the Nazi’s compound, the police would find it. If it is hidden elsewhere, it is likely lost forever.
The fact that Walt shot Jack as he was using “I know where the money is” as a bargaining chip tells me that Walt must have been satisfied with the money he did manage to get to the family.
That was my take on it.