Savings from early renewal on health insurance premiums

All of the health insurance providers are increasing/ changing premiums at the moment on many of their policies in December/ January. Aviva is changing most of theirs on the 1st Jan. Other dates I have seen increases are 28th Dec, 31st Dec and already on the 22nd Dec. My parents were on hospital level 2 with Aviva with a renewal date of 16 Jan. I renewed today and after paying an early closure penalty of 61 Euro they saved 160 Euro due to renewing before the premium increase on 1st Jan. This may be of interest to others whose premiums are due early next year.

Lots of prices and policies are changing on 31st Dec and 1st Jan. Generally they will all be increasing in price. I saved about 70 by renewing a basic plan 2 days early.
My parents this year changed from Aviva hospital level 2 to Aviva 16.1. The plans are very similar. The saving was about 800 each, 1200 rather than about 2000. This plan was found by a broker.
If renewing early some insurers can only start a plan on certain days, ie I could renew my plan with Aviva on the 30th Dec (Tuesday), I couldn't on the 31st Dec (Wednesday).