Any suggestions as to a process for "terminating" the lease or giving notice to vacate? 

It depends on what upgrades you're planning to do, but in most cases you have to wait until the tenant vacates. 

I declined the vacation/deal trip. 

God bless all those who are helping and all those still in peril, you are mountain strong and you WILL MAKE IT.This post is my intent to document and get others opinions on what rental/vacation property owners can do.

New to real estate investing.  I'm sixty years old and was toying with the idea of investing some of my retirement money in a home on Cape Cod.    Can I even break even if Summer rental season is a max of five months,...

The idea of owning and managing vacation homes that provide memorable stays for travelers excites me.

So, $5k/$20k = 25% return on your investment.This is a very simple example that ignores the rental income vs any mortgage payment (taxes & insurance, etc. would be the same in both examples).To increase cashflow, you would also want to take the lower payment of a 30-year mortgage vs 15-year.Regarding the purchase:1) Require the seller to have tenants sign a MTM lease or vacate before closing.

There are programs that offer 100% financing for many different people like Veterans, First time home buyers, (Certain states), Medical professional loans also offer 100% (Anyone with a Medical license).You also have Second Home or Vacation home which only requires 10% down.

And most of the damages a guest will do can be covered by these str booking sites insurance.Your budget will prevent you from buying homes in some of these big cities or vacatation areas with tons of str's. 

High-speed internet, a desk, good coffee etc will be different than a family staying for a vacation.