couldn't find a thread for this - I'm looking for a new sleeping bag and I'm not entirely sure which one to get. I need something that keeps me comfortable down to about -10°C or 14°F. Since I want to be stealth camping, I figure it would be bast to combine it with a bivy bag.
My idea was to go cheap on the bivy bag and expensive on the sleeping bag.

My big local chain has two options in my budget: A 90€ Deuter ORBIT -5° which is arguably not warm enough, but I'm not sure how warm I actually need - or a more expensive Mountain Hardwear Lamina 0F that would cost twice as much and be a little overkill.

I plan on putting it on the bag of my motorcycle, so volume and weight are not something I'm too concerned with.

also sleeping bag general I guess