That's where you should have planted them in the first place. Never plant a rhody near a driveway where compacted snow can result due to snow shoveling - those branches break very readily.

Your backyard is the best site (based on that high shade). Hope that your trees are oaks and not maples or walnuts. If they're in the 'lee' of large conifers, make sure to plant them away from them - they have a tendency to dry out nearby plantings.

Some rhodies do much better in shade than others. Some won't bloom in shade. It is best when planting in shade to limb up the trees which are creating the shade. This creates a mottled shade that is better for creating flower buds. The PJM family is hardy and does well in shade but the ones that bloom in April can get frosted after they start blooming and loose all of their flowers. Please remember that when looking for plants. I have a list of ones that do well in "bright shade" which I linked to below:

Here is a link that might be useful: Shade Tolerant Rhododendrons and Azaleas