Hi all!

I'm hoping one of you knowledgeable folks can offer me some advice on an upcoming award flight I'm taking. I'll do my best to keep it simple.

I currently am booked Toronto to Kauai, returning Maui to Toronto (AC/UA flights).

I'd like to make two changes and will incur the fee to do so.

1) I want to replace Toronto with Montreal as the starting/end points. There is no longer availability on either of the California to/from Hawaii UA flights, but there is availability to/from Montreal that would allow me to connect to my current UA flights to Hawaii. Is it safe to assume this can be done?

2) On my return flight, I'm currently flying Maui - SFO - Toronto [Montreal, hopefully]. I now have the time and would love to visit my folks living just outside of Vegas. Could I feasibly change my return from Maui to Vegas (via SFO), stop there for a few days, then continue on from Vegas to Montreal (there's even a nonstop on AC that's available)? In other words, could OGG-SFO-LAS-YUL with a stopover in Vegas qualify as acceptable routing?

I figured I'd ask for wisdom here, as I find it's always more successful when you call CO to have dates and flight numbers that appear available online ready to go. Thank you so much!