@mpumilia You can get around the ACA system to get 2019 rates by indicating that you have change of life events and it will let you proceed to get current rates. 2020 rates will be available starting in Nov. You may be eligible for premium and share of cost subsidies next year since you will both not be working. Your income will be calculated using your mother's IRA RMD inheritance, interests and dividends from your taxable accounts and whatever amount you want to withdraw from IRA and roll into ROTH.
If you are eligible for subsidies then ACA is likely to be cheaper than COBRA and private individual health insurance. If you are not eligible, you are most likely going to find private individual health insurance cheaper and better than ACA. ACA rates without subsidies are always going to be most expensive and have the worst coverage, because the rates are averaged out with the healthy and the private market-rejected very sick group of people. Without ACA subsidies, you will need to compare oranges to oranges between COBRA rates and coverages and those in the private individual market. Insurance brokers don't get commission from ACA plans so you will first need to find out whether you will get subsidies or not using the ACA site. If you are not going to be eligible ffor ACA subsidies, then you need to connect with broker(s) to find all available private individual market plans.
I was on ACA with full subsidies for premiums and share of cost for the one year after we retired. My premium for their best gold plan was $161 per month and max out of pocket of $850, with $5 copay for PCP and $10 for specialists. No kidding. However many of the best specialists in the area did not take that insurance. I moved to the private individual market the following year and picked the best plan where I could see the best specialists -yes I have many medical issues. Our income also would not qualify for any subsidies. The best ACA plan which many good doctors would not accept their plan, costs more than the best plan in private individual market which has much better doctor coverage.
If what I have written above is unclear, please holler.