This will be my 3rd winter with a Lamina 0. I got it off the STW classifieds after some good experiences with a lighter Lamina. Lovely bag. Very warm for its weight and bulk. More easily cared for than down and will put up with some dampness.

Thoroughly recommend

I’ve got one of the tesco down sleeping bags. Used it the past 3 scottish winters now. Regularly low single and sub zero figures. Absolutely astounding value, think i paid £40 and it packs down to a ball 6″ diameter.

Bit confused about what you actually want:

Do you want compact and lightweight?

Do you want true UK 4 season or -10c?

Do you want synthetic or down?

Do you want pukka kit or Tesco crap?

What’s your budget?

I suspect if the OP bemoans Tesco being out of stock he’ll have a heart attack if he looks at PHD… 🙂

Your concerned about bulk and you want a four season synthetic bag – it’s not happening I’m afraid ..
Your best off with an oversize 1 season synthetic bag to manage the damp and layering up inside – down clothing is best to compensate for bulk – Ultimately though one needs to bite the bullet and accept that damp UK winter conditions do require a fairly bulky sleep system if you want a comfortable night’s sleep ..

To get to -10C, low bulk and low weight, you’re in the 750g down fill area. A decent quality one will be lighter and more compact than your Alpkit 800 but they are essentially in the same area temp wise.

You should be looking at Rab/Mountain Equipment down bags with ~750g fill or PHD if you’re feeling fruity. Their kit is fantastic but top end and made in the UK so price wise more than the equivalent Chinese/East European down filled/made bags. Whatever you decide, £150 will buy you a s/h bag, new is going to be well north of £200.

<edit> PHD do some really top end 900/1000 fill rate down bags which means you should be able to buy a lighter bag for similar temp performance. HOWEVER, they are very, very expensive. I have a 500g fill bag like this that was well over £400!