Winter birthday parties for kids

As a summery and active sun mum, I'm struggling to think of venues for a winter birthday for my future 1 year old (turning 1 - July 2026).

I've always imagined his birthday to be picnic blankets, BBQs, parks and nature, but obviously highly unlikely in the wetness of winter.

I was always planning to go all out for his first birthday and then keep them smaller in the future.

All out at the moment would look like 20 couple friends and their kids (from newborn to 6) as well as family.

Looking for some awesome winter party suggestions catering to the smaller of kids 😊🙏🏼

(Yes I know it's early, but have been to while bunch of birthday parties lately so it has me thinking)