He doesn't even involve congress in his autocratic decisions at all, so capturing control of the House or Senate won't stop him from keeping the border wide open. Plus, he has his own henchmen in the Courts to squash anything a Republican congress would require.
Also, Biden has the veto power. So even if a GOP Congress passed some bills to deal with issues such as the border, Biden would veto such legislation. No way there would be 2/3 support in Congress to override such vetoes.
Not just the courts. The fact is his veto will never be overidden. Nothing is going to get done at all. You can bet on it.