Ordinarily the quickest way from Wembley to Heathrow is bus to Ealing Broadway then Liz Line - about 75 minutes. After a major event that's out of the window.

So, you're either looking at a driver or TfL services that don't involve roads.

The expansion of Wembley Park station has made queues leaving the stadium move much quicker, but nonetheless you can still count on it being at least 15 minutes from joining the queue to being on a train. That's not even including the time taken to get from your seat to the queue in the first place, which could be another 10 minutes or more if you're seated the wrong side and don't know your way around the place. So, allow yourself 30 minutes to being on the move.

I would also second leaving your bags somewhere en-route, which ever option you choose. You really do not have time to go back to a central hotel unless it's very close to your routing.

The tube will take you to Baker Street on the Metropolitan Line then change to Circle/Hammersmith & City for Paddington. That's roughly 40 minutes, putting you there at 7.10pm if the game finishes at 6pm. Collect luggage, get on a Heathrow Express and you're at the airport by about 7.45pm, 8pm if you use Liz Line.

You could also consider going to Wembley Central, Overground train towards Watford, then a driver. That's more predictable in traffic terms, and the station might not be quite as busy, but would involve more pre-game hassle depositing luggage somewhere.

If you use a driver from close to the stadium, I would think about walking towards Harrow (the Preston Rosd part) through the residential streets around Wembley and being collected there - it might be a 45-minute drive from there on matchday. So you're looking at 20 minutes of walking, plus 10 minutes to get round from your seat, plus up to an hour including getting your luggage - plus you need to co-ordinate meet time and place with your driver unless you want to risk an Uber being close. You'll need to find private luggage storage through one of the various apps. So more hassle, probably more cost, but likely a time saving of 15-30 minutes.

Personally I'd probably take the better certainty of public transport, but all your options involve a certain amount of squeaky-bum time.