you dont have to accept even 1% downtime in a month there are alot of companies with good uptime i myself running hosting business for the last two years and we hardly restart our servers once or twice in a year for maintenance.
When you choose a hosting provider that offers 99.9% uptime, expect that at the worst you will see 7 hours of downtime per month (this is what most providers market).
I have used many top hosting provider for keeping my website LIVE with good uptime. As i was dynamic website. But a solution for me was using cloudflare CDN, now my site is 100% up always