AC outdoor fan stops blowing intermittently. Need advice.

Our AC unit is an original Lennox that is 17 years old (uses r-22). We purchased the home two years ago knowing that we'd have to replace the unit in the near future. Our realtor (a friend) paid for 2 years of home warranty, which we still have currently (Ameircan Home Shield).

A few days ago we noticed that our AC was not cooling the house. Went outside and noticed the fan was not moving and there was a loud "hum" coming from the unit. Turned it off and the sound stopped. We tried it again after an hour or so and it started right up and it started to cool the house. Then after awhile it would stop and the same "hum" would start and the fan would stop working.

I've read that this could likely be a bad capacitor.

I called our AHS to get a service tech out and they'll be here tomorrow. I'm not a fan of home warranties however, this was paid for by our realtor so I feel we might as well use it for the time being. We also have a "free service coupon" so there was no cost at all to get someone out.

Now, after reading reviews of the company that is coming out, I am a bit concerned. They have many, many 1-star reviews on Yelp (no surprise) and most reviews (recent ones) say that they are trying to get customers to pay for r-22 because AHS doesn't cover that cost (they cover up to $10/lb for refrigerant). So I'm definitely prepared for them to suggest the same to us when they come. Reviews also said they have refused to do any service until the refrigerant is added (definitely a red flag for me).

My question is this: Will adding refrigerant help get us through a couple of more months? Or is that not even reasonable and not something I should do? I'm sure that our refrigerant is low, there is no doubt about that as our splits when tested prior to summer were at like 10F, so I know things are looking good for our unit. We were just hoping to get through this summer and get a new unit installed later in the year (or early next year).

Any thoughts on how to counter if they tell us we need to add refrigerant?

Thanks for your help.