I would look into a quilt. They are much better for regulating temperature. When its cold you cinch it down and stay warm. When its warm you open it up and stick limbs out until you match the desired level of insulation.

I am a big fan of my EE quilt (no other affiliation than a happy customer). You can get a 30°F apex quilt in long that weighs 24 ounces and costs $215: https://enlightenedequipment.com/enigma-apex-custom/

20°F quilt is just over 30 ounces and $230.

They also make it in extra long, but that is for people over 6'8"