You're in pretty good shape. I think the big need is to get your spending down in retirement, even if you make only smaller changes now. If retirement lets you optimize your food buying/growing/cooking, lose at least one car, stop commuting, maybe replace some kid expenses with time (volunteer with sports groups?), get more of your fun and health from biking or walking, and learn to do the basic house maintenance yourself, you could easily get your expenses down into the $2300/mo range, perhaps with a better and healthier quality of life.
That would seem to call for $690K in assets at a 4% SWR, but remember, you have extra loot coming in as you age. So you really need savings to generate a maximum of $27.6K annually until 55 (when your locked in RSP becomes available), $17.6K until 60 (when you can get CPP), maybe $9K until 67 (when you get OAS), and virtually nothing after that! So 440K in your unlocked assets fund will more than carry you after 55, and you'll need another 10K a year to make up the difference between retirement date and age 55. (Actually a little more because of taxes, but as a couple you'd pay very little on $27K a year.)
Assuming your actual monthly income (after taxes, CPP, and EI) is around $4500 (because 35% is your marginal rate, not your effective rate, right?), you have about $18K a year to sock into savings, plus a $5K tax refund if you're maxing out your RRSP contributions, and about $14K in growth of your existing non-locked investments. $37K a year added to your existing $350K.
You can retire in three to four years.
(Mustachians, jump in and tell me where I'm wrong.)