In the absence of a shed or basement, I would say the mudroom seems like the logical choice here. I would not do an outdoor rack because of exposure to elements and possibility of theft. You do want easy access to the outside.

In my old house, I had a basement, so I would carry it down the stairs. We have no garage or basement in this house, so I had mine in the storage shed, but now it is in a storage closet off the back of the house where the water heater used to be (we got a tankless mounted outside so we now have that space).

Even under the canopy, the bikes are going to get wet when it rains, unless the rain falls down absolutely perpendicular to the ground. And you have the added factor of the sun, beating down and drying out the seats, etc. Plus the risk of theft--I've heard of wheels and seats and water bottle racks being stolen, when the thief couldn't remove the entire bike.

My brother has two of the racks you are thinking of in his sunroom, which doubles as his mudroom and bike repair room (it's got more bike parts than the local bike shop, if you ask me). He likes them; says it is very easy to get the bikes on and off.

My son, who is an avid bike rider, stores his bikes inside on a freestanding rack that holds the bikes vertically. The rack holds at least two bikes, is made of sturdy black metal, and takes less space than storing the bikes horizontally.

Have you heard of Cycloc? It's pretty cool.

Here is a link that might be useful: cycloc