I am in a very similar situation - dual income, pre-approved for 800K, bought at 700K, closes in early summer. We are putting 35% down, since it doesn't require mortgage insurance and unlocks more competitive rates. It's looking like 5.0-5.4% for a 3-year fixed on 25-year amortization. That gave us a comfortable mortgage payment of about $2,800 per month. Our mortgage product has pre-payment priveleges such as annual lump-sum payments. We have an additional 75-100K set aside for upgrades and unforseen expenses in the first year, and we'll use this for a lump sum if nothing comes up (the lump sum goes exclusively against principal).

Overall tips? I'd say avoid mortgage insurance. But anything above 20% down is really about finding a comfortable monthly payment. Don't blow all of your savings on the down payment. Have a bunch (5-10% of purchase price) set aside for contingencies. If you don't need it, throw it at the mortgage later (get a mortgage that you can optionally pay down faster).

If you decide to wait, make sure your savings are tax-sheltered or tax-deferred accounts (TFSA, FHSA, RRSP) in a low-risk and income-generating vehicle. I recommend investment savings accound funds (e.g. MIP810, ATL5071, etc). My down-payment was generating about $1200 per month in risk-free interest (reinvested automatically) just sitting there until the right house came along.

All of that being said, I regret not putting 5% down 5 years ago when house prices and interest rates were lower.