Greenhouse help needed

I bought a an 8ftx6ft greenhouse in the sales in September so i could raise my seedlings in it.  My dad very kindly came round with this pariffin heater today:

http://www.diy.com/diy/jsp/bq/nav.jsp?action=detail&fh_secondid=9218863&fh_view_size=10&fh_location=%2f%2fcatalog01%2fen_GB&fh_search=parafin+heater&fh_eds=%c3%9f&fh_refview=search&isSearch=true

I think it will be too small for my greenhouse but dad insists it will keep the frost out and he has used many a parriff heater before.  He also says i can portion a bit of my greenhouse off  so i am only heating a small part of it ...any ideas how i do this?

Or should i try and change it at B&Q for the bigger parriff heater?

I reckon it will be fine (depends how cold it gets of course!). B&Q site says it will look after a 4 sq.m. greenhouse - which is only a smidge smaller than yours.

You could create a greenhouse-within-a-greenhouse using a sheet of plastic, or some bubble-wrap (or a 4-shelf grow-house or similar)

If you are thinking of buying your own I recommend Gas rather than Paraffin.  Less condensation / humidity and more control.  "Fuel" might be cheaper too (particularly if you can only get Paraffin locally in little 1 gallon plastic containers).

Edit: Was posting at same time as andy135