The brief answer is insurance depends on the specific market and the risk pool of insurers they insure and the other variables considered for each insurer such as their age, claim history, number of vehicles insured, any bundling of insurance such as home owner's and /umbrella policy. Some insurers like USAA are limited to only military members and the numbers won't have any bearing on what you are looking for. So, it is difficult to get an absolute answer from here. Your local Tesla Owner's club members for Boston and immediate vicinity area may have numbers for a specific insurer closer to what you are looking for.
That said, in MD , when I bought my 2017 Tesla Model S and shopping for rates for a total of 3 cars registered under my name bundling with home owners's insurance and an umbrella policy I found out that insurance for MS in 2017 in MD was close to $1600 a year in spite of many yrs of driving experience and no accidents. The next year for my 2018 MS it went up to $1800 per year without any claim history. I was already told by State Farm ( SF was the cheapest for my bundling in 2017 compared to GEICO, Progressive, etc etc) that for my 2022 MS my rate will be easily $2000 this year. Go figure! I was told Teslas cost a lot to insure because of the sensors, build, and parts availability. I think I will pay what they ask for all three cars and my bundled policy in my area where insurance is higher.