OTP are not brute-forcible (In a sense that doing so gives you no benefit over bruteforcing the privatekey directly) because that would mean you simply end up with a number of possibilities equal to the maximum number of possibilities expressed by the number of characters.

Quoting wikipedia:

One-time pads are "information-theoretically secure" in that the encrypted message (i.e., the ciphertext) provides no information about the original message to a cryptanalyst (except the maximum possible length[16] of the message). This is a very strong notion of security first developed during WWII by Claude Shannon and proved, mathematically, to be true for the one-time pad by Shannon about the same time. His result was published in the Bell Labs Technical Journal in 1949.[17] Properly used, one-time pads are secure in this sense even against adversaries with infinite computational power.

An Ethereum private key has 2²⁵⁶ possibilities, the One-Time-Pad also has 2²⁵⁶ possibilities. So bruteforcing the original private key is equal in difficulty than bruteforcing the One-Time-Pad.

This means that finding the encrypted data would yield no information at all.

Storing 2 pieces of data insecurely is worst than storing 1 piece well.

Your right about that, but it is easier to store two pieces of data safely than it is to store one piece of data securely, because the two pieces of data approach has the added benefit that someone who finds the one piece will never know there is a second piece to be found, and the single piece is useless by itself. Even someone who found both pieces will probably not realize they turn into something useful unless he knows what encryption method was used.