I've drawn together some of the wisdom of the Montessori Homeschooling Community and asked them for their top tips to get through schooling at home at this time. We are all in this together and as these experienced homeschoolers would tell you this is not normal homeschooling!
Maria Burke says:
During this time when you are home with your children and are worried about whether or not they are getting what they need or whether they'll be behind, remember this...learning isn't just about academics.
If you take a moment and think about how you want your children to "be" as people when they grow up, you will likely respond that you want them to have empathy, be kind and compassionate, be respectful, and have perseverance, among other traits. Use this time to show them how to react to adversity and how to be flexible. Help them along this path towards the humans you want them to be.
It's okay for you to use alternate forms of education right now. Documentaries and audiobooks are plentiful. Cooking or baking can be a way to integrate mathematics, science, and language. Playing games can lead to many different skills. Cooperative skills can come from games or play.
You've got this!
Vanessa from Mama's Happy Hive says:
If your children were in Montessori school... don't worry or stress during this time by trying to create the perfect Montessori environment at home. I am honestly having a really hard time keeping up with homeschooling right now and I was homeschooling before the Covid-19 virus arrived. It was easier for me to homeschool before the virus because we could mix things up. One day we would take a field trip, another day we had homeschool support school, another day we had a playdate, and we had sports/swimming lessons. All these things helped to mix it up and we were not home 100% of the time going stir-crazy. So please take this time slowly. Do fun things together and don't stress! You do not have to have the perfect Montessori environment at home during this time. Get your kids involved in helping out at home with Practical Life Skills. Do art and music and gross motor skills - such as yoga and dancing together. Take one day at a time. Academically the kids will bounce back next school year! So don't worry. 
One last thing... read lots of books together!"
Jennifer from Branch to Bloom says: