Baker Street is a safe bet. Can get from there to Hive in 20 mins or so too

You need to end up on a Northern line tube to Edgware, then get bus 79, 186, or 340 to Canons Park station. When you get off the bus, head back the way the bus came for about 150 yards or so, ground is on same side of the road. To be honest the beer at the ground is better than the local pubs, and it's pub prices too (though this is London pub prices, not Fev pub prices

). What's more, you get us lot for company!
There's also a bar under the stand if you get thirsty during the game.

*** edited because I didn't realise the Jubilee line was shut ***

Think the Jubilee Line and Metropolitan Line are closed on 10 May. It'll be Northern Line to Edgeware then a 79, 186 or 340 bus, or about 15 min walk.

For watering holes try the Bree Louise on Coburg Street near Euston Station. It's not that far to walk from Kings Cross.

are there any pubs between Edgeware tube station and the ground

Yeah you're right about the tube Reiver, I'll edit my post.

Not sure about pubs in Edgeware. One pub The Three Wishes is an ex- weatherspoons. Been in there and and NRL game has been on. Depends on football and the beer is okay. Perhaps others know what the rest of pubs are like in Edgeware.