If the hotel has security by the elevators what is the best strategy?  Would want to avoid multiple co-workers staying in the same hotel?

and discretely give her a room a key and room number.  Then you go back to your room first, and she will follow a few minutes later.

The provider just may have a hotel key so the problem is solved! Or, you could meet them downstairs, and walk them up, or you could meet them in a specific location and pass a key to them discreetly, or you can leave them an envelope with the key in it at the bell desk or concierge. Any of those would work!

Obvious not a concern with a well known provider, but what if you try someone new in town and when you give them your key and an hr later they don't show up. Yes you lock your valuables away but when you are downstairs exchanging for some new keys, they could be rummaging through your room. Just be cautious.

get a room on first floor?