mbrower, I agree that your $7k/mon (pretax) should allow for very comfortable & flexible fulltiming. The major factors that could impact you are your taxes & medical costs. Depending on the sources of your retirement income, your $7k could result in only $5k after taxes. If most of your savings/investments have already been taxed, then taxes wont be as big an issue as they are on tax deferred savings.
If you plan on self insuring for medical before Medicare kicks in at 65, that can be a risk depending on your retirement age, health and lifestyle. I was self insured for 5 yrs, from retirement at 60, until 65.
I fulltimed for 4 yrs and my avg after tax costs were $5,000 per month. I pretty much did what I wanted, went where ever I wanted and bought what ever I wanted. I'm single, so I was only buying for one. Now that I've transitioned to extended time RV'er and snowbird with summer & winter homes, I still spend around $5k/mon.
Like you I had no interest in workcamping. If I couldn't afford to retire, I would have stayed in business making $250k.
PS: depreciation does not belong in your monthly budget costs. its a reduction in your asset values(net worth) and is handled just like market/investment fluctuations and the capital cost of your next house after fulltiming ends (most fulltime for only a few years). Those should all be factored into the top line, before you calculate whether your total savings/investment nest egg allows for $7000 or $5000 per month spending for the next 25-30 yrs. It somewhat depends on your mix of pension/SS payments vs withdraws from your own savings/investment nest egg, but When you transition to primarily living off say $1.5 million in savings that's only going to decrease every year, you've got nothing coming in to refill that pot, your budgeting outlook needs to change and put more focus on your remaining net worth, rather than your short term costs. Buying a replacement RV or new truck or a future house, is not $350 a month offset by future income, its a $50,000 or $100,000 lump sum deduction from your remaining net worth, never to be replaced. Be sure that your $7k/mon x 12 mon x 25 yrs, has allowed for that.