Dean- I know about B&Q's composts. Have used their seed compost for the last couple of yrs- excellent. Bog standard MP does for the houseplants- no wonder they end up looking starved by Feb each yr though as very rarely feed them. 
Our local weather forecast for the w/end looks snowy! Double checked beeb weather site, recently updated- nothing! Honestly R hand & L hand not knowing what each saying/doing!
If it is going to be rotten on Saturday then can do a bigger shop say on thursday to tide us over. J.