Interesting thought but we really don't have a historical example of that. The Senate is more of an island (look at 1982 bad loss of House seats but essentially broke even in the Senate and in 1970 the GOP gained Senate seats cause we were "due" big time after 1964 and 1958) but having the White House almost always means losing House seats in the midterm. When the President's party has gained House seats it has been slightly.
The elections were that has happened in modern times are 2002, 1998, and 1934. And toss in 1962 when the House went from 437 back down to 435 and I think it was -2 dem but plus zero GOP and the rats gained in the Senate that year.
All of them had in common one thing, the President was very popular at the time. Bush in 2002 was popular (also we had favorable redistricting), Clinton during impeachment with the media telling everyone how great the economy was and how "it's just sex" was popular, Kennedy in 1962 was popular (and I have to think the rats had favorable redistricting with their vast state leg control, the map in Cali was a disaster that gave us 1/3 of the seats on half the vote). There were no Presidential approval rating polls in 1934 but it's safe to assume FDR was popular and the GOP was still hated and reeling.
We were due in 94 and liberals were disliked but anger at Clinton was the #1 motivating factor, without it could we really have won? What if Bush had another read my lips style blunder? Would Kerry have been popular in 2006? I don't think rats were due in 2006, maybe we could have had a 1998 type of "tie" but I really can't see the rats winning majorities without the Bush hate. Maybe Kerry would have been just as hurt by Katrina.
And in 2010 could we have benefited from the hatred of the rat congress if we had RINO McCain at the helm? What if McCain was working with them to pass watered down versions of the crap that Obama eventually passed? Would the tea party still have arisen? Maybe we could have gained in the House cause there was little room to go down after 06 and 08 but a big gain or gaining (and holding) all those Senate seats? I don't know. Maybe if McCain had pulled a sideways Truman and espoused strong Conservative values and vetoed everything but this is McCain we're talking about. Maybe if he died a year in and Palin took over.
If those midterms had gone as you propose it would have been unprecedented. If Obama loses I hope 2014 will break the usual mold. Lots of tasty Senate seats up, we should gain there even if Romney is in and isn't popular.
2 of the last 4 midterms have seen the president’s party gain seats, so I don’t think that the old “rule” applies anymore. And I refuse to build a congressional strategy predicated on allowing the Democrats to win the presidency.