Is living in a cold house really that bad?

According to this 2011 BBC News article the ideal living room temperature is between 18° and 21° C.

According to this 2006 BBC News article the ideal bedroom temperature is 18° C.

Temperatures below this can apparently cause illness, below 16° C resistance to respiratory disease is reduced, 2 hours or more at 12° C raises blood pressure and increases the risk of heart attack or stroke; 5° C increases the risk of hypothermia.

I do like my living room to be warm so the fire is generally on if it is cold outside.  At 6pm on Saturday, with the fire having been on for most of the day, the temperature in the living room was 18.9° C, within the ideal range. However the bedroom was at 12.9° and the bathroom 11.1°.  

I should probably point out that I do not have central heating, I have an electric fire in the living room and I have bought a plug in oil-filled radiator for the bathroom.

When I went to bed at 9.30pm, the bedroom temperature had dropped to 10.1° and the bathroom to 7.9°.  

And I was fine, it didn't even feel that cold.  I actually prefer a slightly cooler bedroom, when I stay in hotels I always have to open a window (if I can) or turn the room thermostat right down.  When I go abroad, I generally leave the balcony door open a little.

Although I do like a cooler bedroom, I don't like to be cold in bed and currently have a sheet, 4 blankets and a duvet covering me.  It is not unknown for me to sleep in pyjamas, dressing gown, socks, gloves and a hat, I did that when I still lived at home, and I have done it occasionally since I moved out.

Sometimes I do wake up in the early hours of the morning and open the window as the bedroom is feeling stuffy, and this can be any time of the year.

Last year a couple in Devon turned their heating off in protest at the rising energy prices, it made the news.  A well known manufacturer sent them one of their heated throws to help them keep warm, not sure they thought that through though.  If the couple had turned off the heating in protest at prices, are they really going to pay to heat an electrically heated throw?

I don't believe I have suffered any ill effects from growing up in a house where ice formed on the INSIDE of the bedroom windows.  I had the usual childhood sniffles and illnesses, but nothing major.

So, is a cold house that bad, or does it just depend on the individual?