Brand new to the forum. I would like to ask for some insight.

I am currently fixing up a summer cottage on Lake Erie that I bought in the fall. The water lines in the community are shut off from Nov 1 to mid March in the community. It will be used almost exclusively between April and October. There may be a time in the future where the community keeps the water on full time. I could see myself or family members using the cottage 80-100 days a year.

Specs: Size-700 sq ft.
1 Bathroom with shower, but there is an additional outdoor shower.
Utilities- Liquid propane furnace and 80 gal hot water heater (both 19 years old). 100 amp service.

I will be remodeling the punched out utility closet due to wall cracks and water drainage issues. I would like to get rid of the chimney(which vents the furnace and hot water tank) which is at the bottom of a valley in the roof and put in gutters to improve drainage.

When discussing my options with a contractor, he suggested going to a tankless system and venting through the wall. Then, we could get rid of the chimney. Because electricity is expensive in that area and I currently have propane to the house he suggested propane.

The hotwater tank is 19 years old but appears to function normally. Does it make sense for me to go to a tankless system?

If so, any advice for BTU or temperature increase (I do not know the temp of water coming into the cottage)?

Any brands that I should look at or stay away from?

Thanks in advance,