My MOT expires next month and I need to renew it, however I have a flight to take in that period and I'll be back two days after the expiration date. I need to bring the car to the airport and leave it there for 1 week, for many reasons it is convenient to me to do so. I was wondering if there's a tolerance time where I can keep my car without MOT. Something like: "Ok your MOT is expired, but you have to renew it in one week".
Firstly, you can have it done 1 month before the expiry date, minus 1 day and you will still preserve the full length of your MOT. This is done for convenience and to allow time for repairs. I always take mine at the earliest opportunity so I can plan for any potential problems.
Example: "If your MOT runs out on 15 May, the earliest you can get an MOT to keep the same renewal date for next year is 16 April." Source
Secondly, if it does expire, you can technically drive it to the MOT test garage if you can prove you have an appointment there for an MOT. In other words, if your MOT expires, you cannot use your car on the public roads (your insurance is also invalidated), however, the exception is if you are driving to have it tested for MOT.
All of this information is at the gov website.
So, just take it now before your trip, you won't lose the month if its within 1 month minus 1 day.