Need advice, New owner

Hey everyone,
I’m a first-time dog owner and could really use some advice.

I have a 5-month-old Havamalt (a small lap dog), and lately he’s seemed a bit down. I play with him a few times a day, let him run around the house, and do short training sessions, but I haven’t been taking him outside for walks because it’s already snowing where I live and he gets cold very easily.

I’m worried that not going outside enough might be affecting his mood. If you have a small dog, especially a cold-sensitive breed, how do you manage winter walks or outdoor time? Any tips on keeping them comfortable, active, and happy during the colder months would be really appreciated.

Thank you so much!