Hi, There are several options for treating your plants for aphids. Here is a link for treating roses with aphids: https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/rose-rosa-aphid Insectidal soaps can be effective and are a fairly safe type of pesticide.
Is this the first time you have tried to overwinter this rose in a garage? I'm surprised to see leaves still on the plant suggesting it did not go fully dormant. The flowering cycle may be thrown off this season as some plants require a cold period to stay in their cycle. If you overwinter it again this winter, you may want to wait until the leaves naturally drop off before bringing it into the garage for the season. Thanks, Amy Jo