Improved Gameplay for Codenames

I really like the board game Codenames. Especially good for 6-10 players. But as is usually the case, I have ideas for improving the rules.

There aren't enough lead changes. It usually comes down to whichever team misses one opportunity loses. Here is how I would like it to work:

• A 6x6 grid instead of 5x5. Increases the intensity, and the opportunity for multi-matches.
• (2) Spy cards. In playing ~30 games, I have never seen the Spy decide the game. That is mostly good, but I would like to make it a bit edgier. 

• No 1-card clues--2-card minimum. Makes it much more challenging, especially with the above adaptation. (One mitigating strategy, if desperate, would be to include a neutral card in the clue.)

(Obviously, the pre-filled 5x5 maps the game comes with won't work. But it would not be hard to create your own 6x6 grids in Excel and print them out.)