A more insulated sleeping pad will not compensate for a subpar sleeping bag.
I also like to sleep cold, but that's a huge difference and 50 F is already the limit rating. For reference, in Celsius it actually says the limit rating is 12 C, and 40 F is 4 C. That's an entire sleeping bag rating down, I myself have two different sleeping bags for these two temperatures.
If it was only a few degrees different, like 8 C, I would say wear extra fleece layers and throw your puffy jacket between you and your quilt.
But this is more than a few degrees and this is not the bag/quilt I would bring. Way too risky. You also don't know that the night temperatures won't dip even lower than the forecast says.
It's a huge difference, and the fact that it's a quilt and not a sleeping bag means it's probably draftier. I like to sleep cold too and I'll bring a sleeping bag rated SLIGHTLY below the actual temperature, but I would not bring this sleeping bag with such a huge difference.
> You ALWAYS need a sleeping bag rated for a colder temperature than you plan to stay at. Sleeping bag rating numbers are designed assuming you are wearing clothes and are rated more towards survival NOT comfort.
Neither of these things are true.
A reputable big name bag like Big Agnes usually advertises the limit rating for men and then comfort rating for women. For OP's bag, 50 F is the limit rating. Limit and comfort rating are the temperatures for hot and cold sleepers respectively, wearing appropriate base layers for the conditions. The extreme, or survival, temperature is much lower than the limit of comfort rating.
I have a sleeping bag limit rated for 6°C, and I've used it in <4°C just fine by layering extra stuff inside it of it like another commenter suggested. I used my puffy jacket INSIDE the sleeping bag as half-blanket on my torso, and had my rain shell around my legs. It was warm enough.
I just looked up the comfort rating on that quilt and it says 59f. That pad is more than capable. But it's not going to make up for that. You're probably going to be cold. What you maybe can do is layer up. Puffy jacket. Some kind of insulated pants like fleece or whatever. Warm socks. Warm hat. But those comfort ratings are already assuming that you're wearing a thermal layer, wool socks, and a warm hat. So you probably need more than that to be comfortable in 40 f temperatures with that quilt.
The pad, however, is more than capable. I have one. It's very warm. I just don't think it's good make up for having an inadequate top layer.
Not sure what temps you're planning on camping in, but if you think you'll be in 20 degree nights, get a bag that is rated for 0 or 5 degrees. Unless it specifically states the rating is the comfort rating. You'll also want a pad above r4. I'm in the southeast and ONLY camp in the winter. Took me a lot of trial and error of finding the right gear. Weight, cost, size, and quality. I absolutely love my set up. I got a big agnes fly creek off marketplace from a guy that used it twice. Big agnes Anvil Horn and it was on a great sale. And thermarest neo air xlite. Super comfy pad and it was the one thing I paid full price for and actually said fuck it. I used a few other pads and just wasn't happy. I move a ton and needed something comfy and wide but also with a high enough r rating and not heavy.
The older I get the thicker the sleeping pad...
Where I live, I need 3 distinct sleeping bags - warm weather (Big Agnes), shoulder seasons/early winter (Nemo), and extreme winter (Big Agnes - takes up the whole backpack!)
I have an REI half dome tent - big enough for weekend camping, small enough that I could backpack with it if I'm not using a hammock. I also have several Coleman Sun Domes as lenders, and my boys each have a Kelty when they don't hammock.
For front country camping, a nice comfy camp chair is worth its weight... consider a lightweight backpacking chair as an addition or alternative. You can enjoy a lightweight camping chair in camp, but hard to take an XXL rocking camp chair backpacking...
Consider hammocking, too, but that's a whole additional rabbit hole to travel down.
BottleCoffee
