First, let's round up and assume that you live off of $40,000 p/a. Your annual RRSP contribution increases by about $15,000 (18% of gross), less any pension adjustment. Some quick math and here's what I end up with:
- RRSP: $15,000
- Tax bill: $15,000
- Net: $55,000
You should still (theoretically) have lots of money to contribute to your TFSA and not rob yourself of the biggest benefit of the TFSA, the compounding interest that you'll never pay taxes on again.
I don't know if you have already, but if you earn a steady income (every two weeks) and get your taxes withheld throughout the year like most employees, you should fill out a T1213 every year. Simply mark that you will be contributing $575 per cheque to your RRSP. Mail it in, it will be approved by CRA, bring it to your employer and they will not withhold tax off that $575, so in reality it will cost you more like $400. You won't get a big tax return every April, but it's better to get it right away anyhow.
Second, the whole minimum withdrawals thing with RRSP doesn't happen until you convert your RRSP to a RRIF which can happen as late as the year you turn 71. Up until that time, you can withdraw as much or as little as you want and it would taxed as regular income. Let's say your FI# is $1m and you reach that at 50 years old. You have $700,000 in your RRSP and $300,000 in your TFSA. You could withdraw all your spending needs out of your RRSP and pay very little tax and let your TFSA grow tax free until later. This would mean your withdrawal rate is 6%, well over the recommended 4%, but it would nicely drop the value of your RRSP before you turn 71 and roll into RRIF. During this 20 years, your TFSA grows from $300,000 to over $1m at a 7% return.
Third, on the clawbacks thing, I'm almost positive that by the time we retire and are eligible for old age benefits, they will include TFSA as income (although not taxed) and it will affect your eligibility for OAS and GIS. All it would take is a slight change in the tax code, it makes logical sense and would be an easy sell to the public, especially in our era where responsible people who actually save like they're supposed to are viewed as rich and special.