Hi,
The more ties to the UK that you have, the fewer days you can remain in the UK and continue to be not tax resident. If you only have one tie, then you are limited to a maximum 120 days in the UK. If you stay any longer and you become tax resident.
You can see the guidance thst explains those ties here:
RDRM11510 - Residence: The SRT: The ties test: Introduction
Your husband would need to look at this based on his own circumstances.
We cannot provide financial advice, you would need to seek professional advice.
Thank you.