There are so many great interior design / home design brains on here I figured I'd see if anyone could give me some ideas that I'm not thinking of / give advice on which of the ideas I have make sense.

Attached is a photo of the style of home we live in (this is not our house but it's exactly the same design / size), and what the upstairs layout is like. We have 4 (small) bedrooms and 1.5 baths. Downstairs are an eat in kitchen / dining combo, living room, mudroom / laundry room and half bathroom. The addition on the right is our playroom, but the previous owners built it themselves and its pretty crappily done / there's no real foundation beneath it / I think we would need to redo it if we added a second story to it.

Our only full bath is upstairs and is TINY, like when we give the kids a bath I can't even kneel in front of the tub because the toilet is so close to the tub, and the door hits the tiny vanity when it opens.

We'd like to:
- Enlarge the full bath, it doesn't have to be by much, just a couple feet wider would be enough.
- Add a bedroom, possibly an actual master? Our room right now barely fits our queen bed and two dressers.

I have a bunch of ideas on how to accomplish this but I know nothing about building / architecture so I'm not sure how feasible or expensive any of these would be! What do you think the cheapest way to accomplish this would be?

1. Tear down existing playroom, build a two story addition - keep first floor as playroom, second floor extra bedroom / master, enlarge the bathroom.

2. Tear down existing playroom, build a garage. This would allows us to then finish the entire basement (since we could move everything in our basement currently into the garage), with a playroom and bedroom down there.

3. Add a third story / finish the attic - is this even possible? I don't think the ceilings in our attic are quite tall enough to just add dormers, so I'm thinking no? But this would be super amazing since it would give us a ton more space!