Is it permissible to travel to Europe for work with the intention of repenting from ill-gotten gains, knowing that staying in the home country might lead to reverting to such practices?

You must immediately stop the forbidden work. The conditions for a valid repentance are: ceasing the disobedience, regretting it, and resolving not to return to it, along with seeking forgiveness. Your statement, "I have decided to repent on the condition that I travel to work in Europe," is ill-mannered towards Allah and an injustice to yourself. Repent to Allah immediately, whether you travel or not, and seek lawful earnings. For whoever gives up something for the sake of Allah, Allah will compensate him with something better: "And whoever fears Allah – He will make for him a way out and will provide for him from where he does not expect." What you have earned from the forbidden work must be disposed of by giving it to the poor and needy. You may take from it what suffices your need if you are poor. The idea that staying in your country exposes you to the need for unlawful money might be one of Satan's tricks. Therefore, we do not advise you to travel; rather, stay in your country and seek lawful earnings. A little good and lawful is better than much evil and unlawful: "Say, 'Not equal are the evil and the good, although the abundance of evil might impress you.'"