I support this idea, happened to me a couple of times and i know the feeling. It is annoying when you wotk hard for the spree and it simply vanishes when your enemies tend to do it.
But, continuing it even after map change is done is also a bit unfair, you will find sprees over 200 easily so I think if the president survives, spree ends and when president dies where there is no Vice President, i say let the spree continues.
So +1