First, you need to think about your goals - For instance, if your life goal is to give to charity, you can do QCDs up to $100,000/yr from your IRA that can count as part of your RMD without incurring taxes on the gifted portion and if you leave your IRA to charity in your estate, it is not taxed. Obviously Roth conversions are not so attractive in that case.
If you want to maximize the money passed to your heirs, then to complete your model, you have to think about their situation. They have 10 years to liquidate IRAs, so if they are high earners, your bequest may land on their high earning years and maybe taxed at an even higher rate than you. Or if they are in lower paid jobs than you, then maybe passing an IRA to them will lower your lifetime tax rate vs. pushing real hard to do Roth conversions.
You also need to think about the fact that you are older than your wife, so she may have several years at single tax rates and as others have pointed out, the stash may grow before RMDs.
You need to model the situation, my intuition is you should be targeting to get to the top of the 24% bracket for the next few years. Also, as you build up a Roth, put only stocks in the Roth and maintain your asset allocation by adding bonds to your IRA, that will also help slow the growth of your IRA.
A run through of some modeling options -
I recommend starting with i-orp.com (scroll down to Extended Input), its tax model has some gaps (last I checked it used the current year income instead of 2 years prior for IRMAA, no AMT, no NIIT, no deduction phaseout), but it gives a whole life plan from some simple inputs. You would then run various cases using the Partial Roth Conversion inputs. The program designed to tell you how much you can spend each year and end up at zero left at end of life. If you want to leave an estate, you enter your desired amount as Plan Surplus. When you do Roth conversion studies, you need to tell the program to use the same asset allocation in all your accounts or it will inherently mix the effects of doing a Roth conversion with the benefits of holding more of your bonds in tax deferred to slow its growth.
If you are spreadsheet savvy, you can use the Bogleheads.org Retiree Portfolio Model that is free at their wiki. It is more flexible in year by year entries, but everything is manual, so you would have work out your own plan. Personally, I find the input layout a little confusing and it still has some tax gaps like AMT (that can bite singles pretty easily), existing capital gains, HSAs, non-deductible contributions to t-IRAs. The new beta has a unique cool feature that allows you to see what happens if you put your bonds in your traditional IRA and your stocks in taxable and Roth - in general you don't need to convert as much to Roths when you do that.
Of the programs I've used, Pralana Gold ($99 1st year, $49 renewal, requires Excel, no substitutes) has the best tax model and flexibility, comes with a good manual with screenshots. There is a free Bronze version that doesn't do too much but lets you get a feel for the layout and usage of the paid program. It includes tax nuances that you may be facing, particularly after one of you passes - things like NIIT, AMT, deduction phaseouts. The program is not as automated as i-orp, but much more automated than RPM. The program reports both the net worth and "effective $", where "effective $" has applied your lifetime average marginal tax bracket to the t-IRA left in the estate to approximate what your heirs have left.
In general in Pralana Gold, you would do Roth conversion studies similar to i-orp, where you keep the asset allocation in each account the same. If you love numbers and really want to fiddle with it, you can use the four asset allocation changes allowed during your lifespan to manually play with asset allocations in various accounts to approximate the stocks in Roth, bonds in t-IRA approach, but that is tedious.
