This means, on the Senate district level, rural states' votes continue to be more heavily weighted than urbanized states with the result that 27 state legislatures are Republican controlled, while only 17 state legislatures are Democratic controlled. The rest are split.
Consequently, the immediate result of repealing the 17th amendment would result in 54 GOP Senators, 34 Democratic Senators, with the rest being a tossup. The Republicans would gain a majority in the Senate.
I think you are missing a couple of points. First, Article V of the Constitution provides that "no State, without its Consent, shall be deprived of its equal Suffrage in the Senate." Since Article V deals with the amendment process, this is the one remaining absolute prohibition in the Constitution, which cannot be removed even by amendment. This rules out a number of solutions, such as increasing the number of Senators for more populated states.
The problem is not the 17th Amendment, which deals with the manner of electing Senators, but with the equal allocation of Senators (two) to each state. It really doesn't matter for your argument whether these Senators are elected directly, by state legislators, or for that matter chosen by lot!
If there is a remedy, it would be for more populous states to decide to divide into multiple states increasing the number of states and thus Senators. I'm not sure this would accomplish much. Many of the larger states have a urban/rural divisions that would not change the results much. For example, if Chicago became a state separate from Illinois, it would select two Democratic Senators and downstate would select two Republican Senators. Currently there are one of each, so the number of Senators would increase while the balance would remain equal.
But what about a state like Texas? An argument can be made that four or five large cities in Texas could become separate states and that a majority of these would probably be Democratic (Austin for example). Since there are no Texas Democratic Senators today, any pickup would be a gain.
It's a fun game to play, but I just don't see how this kind of restructuring could have a major lasting impact on the balance of the Senate.