Sleeping bag recommendation

For the last few years, my son has been sleeping in average sleeping bag. Not cheap but also not rated for cold weather camping. I'd like to get him an upgrade for Christmas and am looking for suggestions.

He's tall- about 6'2"

Looking for something that would work both for hot summer campouts but also be warm enough for winter campouts. Is that even a thing?

I read that you buy a liner that gets added in to provide more warmth for winter campouts.

Is REI a good option?

Thanks for any feedback