Tier2 dependant extension

Hi all,

Few questions regarding tier-2 dependant extension..
I entered uk on tier-2 dependant visa in nov-2015..
Got extension in 2017 and it is valid until March-2020
My spouse who is main applicant got his ilr recently based on tier-2 5 years route...
Can I stay on my current visa until it expire and then apply for extension which will be in march-2020?
As I will be eligible for ilr by nov-2020 , can I get extension for only 1 year instead of 3 years?( which could save me nhs fee)
What documents do I need to submit during tier2 extension.?
How can I prove that my spouse got ilr based on tier-2 5 years route?

Thanks

1. You current visa remains valid.

2. An extension is for 3 years as stated in the immigration rules. You cannot choose to apply for a lesser period.

3. Maintenance funds, passport, brp, proof of cohabitation etc.

4. You don't need to prove it. HO know the rules and your and spouse immigration history.

Thanks CR001.
can we submit 3 months bank statements of joint account as proof of cohabitation?