The VHCOL is the spin that has our stories differ (and DH and I are older and now retired) - and we had one income since children were 3 & 5 until age 60 and re-entry to job market was at lower pay and less than FT hours for 5 years (and re-entry was also after successfully battling aggressive stage III cancer). DH grew up really in somewhat more working class family situation (although with a thread of higher education honored/respected) and my father had the drive and ability to do well with his own business (but also died young due to smoking effects 20 years after he quit - died at 64).
Certainly college selection/costs can very depending on what is selected and opportunities for merit scholarships. If student takes longer to totally launch (due to graduate or professional school and parental assistance) - those factors/decisions on college spending can also come into play when reviewing final nest egg as one gets close to retirement.
Budgeting vacation costs seems feasible with dual incomes.
When you get closer to age 60, you can end up seeing where your children end up living and what your total financial picture is at that time. If you decide to live in a lower COL place and are able to ‘downsize’ in cost of RE and taxes/COL.
I would not worry about your SS because if your spousal benefit is higher, you would go with that number - but also there are unknowns on how SS will be funded and if it will run the way it is now.
However if your DH does retire at 60, it is having the cash flow off the investments for the years where maybe his and your salaries are at their highest. Because of some company bonuses and stock options, DH had a few extra bumps in income 2013, 2015, 2018, and 2019 (and would have been 2020 but he stopped working before the end of the year).
Like you, the current state of our losses in 401k due to the stock market situation/downward trending - the unknowns and the factors entering in giving us a bit of heartburn and challenging our nerves.
The unknowns! I say just continue hanging in with the good things you are doing financially and making the modifications necessary as situations require.
The things you can do well is attention to kids/family unit and helping guide the children with continuing good choices in life and seeking out careers where they can support themselves. Then if they have a SO down the road, the hope is that the SO also has made good choices in life. Right now SIL and DD2’s BF are struggling - underemployed and finding their way. DD1/SIL have 3 young children.