The biggest thing to check for is if you have a volte eligible phone with volte enabled.

Otherwise you’ll be running on what’s left of a 3G network in the US which isn’t super reliable.

I saw several reports saying  calling with prepaid roaming didn't work properly. Data seems to be ok though.. Their official webpage was still advising people about the issue https://www.koodomobile.com/en/help/3gshutdownUS

Also, which phone are you using? I assumed your phone was compatible with us carriers?

Koodo Pre-paid roaming does not work reliably in the US because VoLTE, the US newer standard  is not supported by Koodo for pre-paid customers. You will only get service if you are in a strong legacy T-Mobile signal area, such as a major airport.

Koodo should stop selling those boosters until they fix the problem on their end.

If you are considering a local US SIM, your phone also has to be VoLTE compatible. Mint and Tello IMEI checkers tend to give false positive readings. US street address and credit card are required if bought on-line.

Checklist for compatible phones:

https://www.att.com/idpassets/images/support/pdf/Devices-Working-on-ATT-Network.pdf?source=ESSZ0SSPR00T1EsEM&wtExtndSource=20201020164156_AT%26T+Community+Forums__COMMUNITY_3954573197

Actually they updated things February 22 so that prepaid customers can get access to VoLTE.

As of Feb 22, any new customers will have it automatically added and existing customers need to do something like a sim swap, voicemail pin reset, change phone number, etc to have it automatically added onto their account. (Voicemail pin reset probably being the easiest of the bunch)

I see it says on the Koodo website that starting on Feb. 22, existing customers will gradually be given access to voLTE.  How can I tell if I have been given access, and if I haven’t can I request it from Koodo so that I can use my phone in Florida starting April 20?

We have been in Arizona since the middle of October and have not had any problems with Koodo prepaid texting. 
Phone calls were a bit iffy but now that Volte has been activated they are much better.

Easiest way would be to see if you can enable it in your phone.
Another way would be to see if your phone stays connected to LTE while you’re on the phone with someone.

I can enable it on my phone. But does that mean that Koodo has activated it?

When you look at your add-ons do you see voLTE? If so, I guess you are among the customers who have had it activated. I don’t see that on my account.

If you can enable it on your phone and when you make a call your data still shows as LTE on your phone, then it is successfully working and therefore activated on your number.