Since you already know you and your sister have different ways of doing things I think it would be best if you talked to her now and find out what she expects of you/your dogs before you make the discission to take them. It is her home, and although you are family, you are also guests. If what she would want is for them to be crated nearly all the time, then I think that for their happiness you should make other arrangements for them.
And, yes, sometimes we have to make sacrifices for our Mom's.
As I'm sure they made sacrifices for us. As awful as it is to be away from our babies, the time that we have with our Mom's is limited. Don't miss this opportunity to make some memories with your family.