If you can smell it, I bet it's a rat rather than a mouse. I agree with the others that the only way you can get the smell out is to remove the offending carcass. Cool weather just prolongs the agony. Speaking from experience: it takes a least a week for the stench to peak before declining.
Also, it's very difficult to pinpoint the precise location of the dead animal. You might think a small hole will do the trick, but it may be in a different void or up high rather than along the baseboard. I once thought I had located a dead rat by the smell coming from an electical outlet (niiiiice), but after I had ripped out some trim, carpet and subflooring, I found that the rat had a network of tunnels chewed through the studs. The body was nowhere to be seen. So my destruction was for nothing and the rat stench stayed on. And, that's how I learned how long it takes for the stench to go away.