Lockdown

As my husband is in the building trade and the people who come and do the council work will be also employed either Sub contracted by the council are still trying to work if they possibly can and lost a lot of work in the first lockdown.I'm sure your worried letting some one in your home , if you let them in to do the work and you keep our their way as my husband does and also they wear a mask like he does you will be getting a new kitchen and bathroom which I presume is far better than the one your living with at the moment .As the decision is entirely yours to make the council may not be so inclined to offer the opportunity in the future and be a long time getting it booked in again ?
If you feel that you don't want to that's fine
If you feel that you would that's fine
This virus no one asked for , or did we know how to stop it now we do
Now we make our own choice to stay safe , keep safe by staying at home if we can.
My husband makes a choice to work and work in people's homes if they allow him to and he works by the rules to protect the people he is working for and to protect me a Diabetic .

As per housing agreement, your house needs health and safety issues sorted.
And the most important one is gas checking which is an annual safety check..
It a point of law.
Unfortunately, your anxiety like mine is high, but in life certain things have to be done.
I was trained in skills to find options and keep an open mind and solving problems.
I would ask the kitchen fitters to phone you when they arrive at the house,, if they are in kitchen, you can be in the bedroom, or in the lounge (front room! Too posh?)
Or go the shop, speak to a neighbour (social distancing) go for a walk if it's a nice day!!!
Get the work done, enjoy your new kitchen and your new home.
Hopefully, things have a way of working out.

Stay safe.