If only Severus knew...
However if he had been given all the information in a timely manner Severus could have modified the plan to give himself a chance at survival without harming Harry's. For instance, provoke some minor DE (preferably someone who isn't on Tom's good side) to a fight and appear to lose convincingly. When the time came he could have attempted to convince Tom the other DE was the true master. (This only has a chance of working if Tom doesn't have too much time to notice no improvement in the wand's performance, so Tom shouldn't be told too soon.)
I wonder if the community can come up with additional scenarios?
For this purpose I wouldn't consider getting rid of the Elder Wand completely, because I'm afraid this would have resulted in Voldemort setting Nagini on *Harry*, and Severus wouldn't want that if he knew that Harry had a chance of surviving an AK.