Strep Bacteria Longevity

I have 3 children that pass strep around a few times per year and have some questions that their pediatrician has never really been able to answer.

Most internet sources say the bacteria survives around 48 hours outside of the body but some sources say it can live 6.5 months. Which is true?

I normally disinfect our whole house with bleach water after an infection but this is very time consuming and I’m wondering how necessary it really is based on how long it can truly live on surfaces.

I was also curious about whether or not a person develops any immunity to strep after having it? Their pediatrician’s partner told me that he believed many of their “positives” were antibodies from previous infections but their office does not culture / have a lab, so I’ve always been curious how long a person can test positive for strep after treatment without having an active infection - or if a person has a positive test but no symptoms if they are contagious.

Some doctors tell us as long as we clean doorknobs and toss tooth brushes that we are good but others will tell me to wash their bedding, toss toys that have been in their mouths, any lip care products, etc. Definitely two extremes of advice that have left me curious.

Anyway, these are just some of the questions I’ve had about strep for many years without ever getting any satisfying answers and hoped maybe someone in microbiology was able to answer them more completely!