I agree with Cynthia. Getting a LIR just for the voting periods isn't a good idea. Also, the registration fee should in any case remain the same, as the effort, even for 10 days, is the same, by the RIPE staff.

However, from the timing and tone in the e-mail, I assume that you mean an existing LIR that stops the subscription on 10th of January, instead of 31st of December. In that case, I think closing the LIR a few days earlier is better, and much simpler than creating a new process for RIPE to follow that involves prorating.

Antonis