>35%
You are supposing that if there is no Pres-elect, then there is no House either (as the House terms end Jan 3). But 2/3 of the Senate will continue in their terms including Pres pro tem Grassley.
But the Dems are probably contriving fuckery to ensure that only SOME House elections get hit with delays. So there will be some House on Jan 3, likely skewed Democratic.