Guest arriving in 3 days. Central air conditioning just stopped working!

[Bryn69]

Hi there! Appreciate any feedback! 
I have a guest arriving in three days for a 4 night stay and then have a another guest arriving for a 3 night stay.

My a/c has just broken!! HVAC has been called but finding parts and Freon is difficult during these Covid times! It may not get fixed before guest arrives, or may need to be maintained while guest is here!! Worst case scenario!!!

We are also experiencing high heat in the Northwest where most homes do not have A/c. However, I do believe this is a perk to my listing.  Without A/c, the condo will sit at 82 degrees at hottest time of day from 4-8 pm and cool down at night and in mornings around  74 degrees. 

I have a window fan available for both the bedroom and living room which is a noise inconvenience,  but will cool down the areas. Purchasing a temporary a/c unit is not an available option in my area. 

I have read forums about Airbnb re-homing a guest, but do not know how to navigate this option?  I live in a rural vacation destination that is high demand and other vacation rentals will likely be unavailable and expensive.

 I am concerned because I have the impression he is working from home and needs the space to upload video content for his business. I am guessing  ANY distraction will be a major inconvenience! 

I should know more today after HVAC provides more information on available parts/etc for repair and if/when it can happen. Trying to prepare. And to complicate things even more, I will be traveling down a river and have no access to email, text or Airbnb messaging for two weeks after the day the guest arrives and will rely on a co-host to manage the following:

When should I start communication and what should I offer as solutions? 

1. How do I offer a cancellation? 

2. How do I offer the rehoming?

3. If he decides to stay, should I discount or refund days the A/c  is not working and/or the days a maintenance person is inside the home? 

4. Can I refund in two weeks after I am available for correspondence? Or should I refund ASAP? 

Seeking best strategy!! Thank you in advance! 

[Mike-And-Jane0]

@Bryn69 I would message the guest saying what you have explained here and ask them if they would like to cancel or accept a 15% (10? 20?) discount on their stay if the AC is not working or if they are inconvenienced by repair folks.

[Bryn69]

Thank you!

Repair will be in home for 4 hours on the guest’s last day and I can provide temperature controlled window fans and possibly a window unit. 
Guest is requesting a discount. Does 15-20% seem fair? 
What is the best way to complete this transaction? 
Would I set this up as a refund? 
or as a discount since he has a few days before check in?