British/Canadian moving to UK with Canadian Spouse

Hello,

I am British/Canadian (dual) and married to a Canadian, we are living and working in Canada. I have recently accepted a work transfer to our London office and my spouse is applying for his vaf4a spousal visa.

We do not plan on arranging housing until we arrive in the UK, though my employer is paying for housing for our accommodations for 1 month so we have time to search. I will also not have a National Insurance number until I arrive in the UK.

Will we be ok to submit letters from our employers, and offer detailed information about why we do not yet have this information??

Should we book our temporary accommodation before we submit?

Any insights you could offer would be much appreciated!