Camping Gear for 30 Degree Nights

I will be backpacking in Zion in late March/early April, and night temps at elevation can be in the 30s, much colder than I usually camp in, where being hot at night is the usual problem. I have a single-person 3-season tent, inflatable sleep pad, and my trusty fleece that has gotten me through nights in the high 40s. What is the cheapest and/or simplest way to make this system sufficient?

I am currently thinking a legit sleeping bag like the Kelty Cosmic Down, hand warmers, and an emergency blanket between my pad and the floor of the tent. Or should I go all in on a 4-season tent? They are not cheap, and I doubt I will use it much.

Any other advice is appreciated!

At those temps, you shouldn’t need a four-season tent, just a 3-season with good ventilation.

Don’t skimp on two sleeping pads. I usually bring foam and then an inflatable when winter camping.

Get a liner for your bag and a good sleeping mat. It doesn’t have to be expensive.

Add a fleece buff or scarf and a thin pair of gloves.

The emergency blanket under the pad is a good idea, but it will be slippery and very loud.