Transfer HSA from Optum to Fidelity

Optum charges a fee of 0.03% every month if the balance isn’t above a certain amount, I’m going to open a Fidelity account and make a transfer to avoid the fees. If I do a partial transfer and leave $0.01 in there, will my account go negative and be hit with a large fee years down the track? I’m trying to avoid the account closure fee if anyone wonders why. Anyone have an experience? TIA