With such limited gear when traveling light, every piece gets multiple uses so I’ll tell you what I bring for 90% of my trips. Note I tend to be what most would consider a moderately warm sleeper but not extreme as I’ve certainly been cold before!
I have two quilts, both rated 30 but they are not equal warmth nor weight. I use a thermarest NeoAir Xlite and if it’s on snow, I’ll bring a cheap pad to go under that I got on amazon.
The Katabatic Flex 30 is very versatile and I’ve used it down to mid 20’s. Katabatic is very conservatively rated IMO, I’d expect to be fine down to 20 even with the door open for moisture.
I also have an EE Revelation 30. It is significantly lighter than the flex (16.7 oz in Reg/Reg vs 24.7 L/Wide) but it’s also lacking all the extras so is about 10 degrees cooler and is a bit tighter for my 6’1″, 180lbs. This is my summer quilt, I’d expect it to be good to the mid/high 30’s but more like survivable at 30, even layered up. I have limited experience with it so far but it doesn’t have all the extras the katabatic has plus has less loft so it’s a logic based assumption.
For clothing I bring the following on virtually any non-winter trip:
2 pairs of socks, 1 wool, 1 possumdown if I expect to be wet
1 ultra light silk long johns bottoms
2 pairs Under Armor briefs
1 wool short sleeve hiking shirt I hike in
1 Wool Long sleeve that’s a camp and sleep shirt
1 Montbell down puffy jacket with hood
1 fleece hat
1 pair UL fleece gloves
1 UL Rain Jacket
1 running shorts
1 UL rain pants
On a typical night in the cascades we get to the high 30’s in spring and fall so I’ll wear socks, long johns and the wool shirt and hat with the puffy jacket to start but I almost always take it off at some point in the night. When it’s going to be colder I don’t change much but don’t take off the jacket. If it’s unexpectedly much colder I add the rain gear over everything and a second pair of socks but that’s a very rare occasion and I’d generally end up taking off the rain gear once I got up warm. If I know it’s going to be colder I might bring a sleeping bag liner.