Carinthia - Defence 4

I have a Carinthia Defence 4 which is fantastic but quite a ways out of your budget. But the Army issue medium weight bag is a direct copy of it just without using the G loft down. Comfort down to -10c and you'll be able to get one within your budget.

Thermal undies, preferably merino wool. Carinthia sleeping set up - Defence 4 sleeping bag with Truepin sleeping bag inside. Cover these with a good quality bivvy bag. In such cold you will definitely need a **4+, R-rated** sleeping mat. Maybe invest in some hand-warmers and a hat.

If your intended use case is sleeping outside in winter, you will die in one of those. Buy proper sleeping bag, like https://varusteleka.com/products/carinthia-sa-m05-makuupussi-oliivinvihrea-fi.

If you want simple, low-ish price range and reliable/robust, I can recommend Carinthia Defence 4. It fits your requirements almost - it is not small though. Personally I think it's comfortable although it probably lacks some comfort features.

Carinthia Def 4 and for summer the Carinthia Tropical (both can be combined for more warmth). The Def is usually available at army surplus while the tropical is more rare. In the US the US extreme cold weather sleep system might be easier obtainable.

Carinthia Defense line. Goes to -30 degrees celcius (or more...) and won't break the budget.

Try Carinthia sleeping bags! They are the fuckin best but a bit expenaive

I like my Carinthia but was baffled that it does not have a baffle which to my mind makes it unsuitable for cold conditions.