Lightweight Sleeping bag

Are you going to be dealing with a lot of rain?

How cold or warm are the temperature ranges that you think you will be dealing with?

What is your price budget?

For colder weather the Marmot Helium or Helium EQ down bags works well at 1 lb 13 oz or 2 lb 3 oz for the EQ. (The EQ has a waterproof/highly water resistant shell).
The negative is that these bags are expensive, up to $429.00 for the EQ model…regular bag is 6 ft. An advantage for you is that the Helium is considered to have a wide cut vs. other bags, which is often listed as a negative for warmth.

For a summer/lighter bag, you might consider the Marmot Atom 40 degree down bag, which is 1 lb.

I have this bag too, but in hind sight, I would look at the Marmot Hydrogen (might have the name wrong) 35 degree bag, which does not have sew thru baffles and is warmer for only 5 oz more weight…fewer cold spots.

I have experienced cold spots on the Atom bag.

Hope that this helps.

-Tony

You may find that these criteria are not so specific as intended. There are many options.

Dig into the "Search Forums" "Search Reviews" and "Search BPL" functions. You will find a plethora of opinions.

If you want a quick answer, few would recommend against Western Mountaineering (WM can help you pick a model), but this brand might not be the best choice for you as an individual.

If it's a bag (and not a quilt) you are looking for, I would recommend either a WM Ultralite if you are slim, otherwise a WM Versalite if you are broader. However I don't know what conditions you are looking at for three seasons in New England…you may be able to get away with a much lighter quilt if you don't expect temps below freezing and you're in an enclosed shelter or bivy bag.