We lived in it for about 20 months and then started renting it out in 2022 - current assessed land value is $327,500.  

Is there a method that you recommend when it comes to assessing whether there is a good rental demand in any given area?

They market to dozens of sites, have online applications, and run credit checks (rent payments coming soon).

Due to the extreme conditions this winter in New England he has seen dozens of these claims and there hasn't been one where he has found the landlord to be the responsible party. 

If the option is taken, he agrees to finance it to you, seller financed.That note will be an asset to him if he needs to qualify, two routes:One, make the note so that it is not marketable as the asset is assessed to it's market value, or;Two, set the note up to be purchased later on at a discount if he needs to qualify, the note is sold and all funds then go to his care until expensed.......this is the better alternative.If you just bought it, there will be a 3 to 7 year contemplation rule as to his disposal of assets and he may be obligated  to use the sale proceeds for his care, which he won't have, say in year 7.

Our flapper of choice is:Korky® Plus™ Universal Flapper#1 selling flapper in the USAPremium universal 2" flapper for toilets before 1994Long lastingStainless steel chainPart #2001BPI've used this flapper in at least a dozen toilets.  

They can usually install about a dozen windows in a day but it a good crew they can do 20+.

I am a bidder or the foreclosing entity on sales, cried at the courthouse steps probably a half dozen times per month so, you can opine all you want but you are factually incorrect.

If the assessment is a lot higher I have to say what the heck, why?  

I did about a dozen of these over three years.One source at that time that worked well for finding these properties was www.realtytrac.com.