I have a large Rhinehart for broadheads and an even larger Morell bag target for field points.
EDIT: I don't have a crossbow. Those targets are used for my Elite compound bow. I assume Rinehart and Morell make targets suitable for crossbows. Both companies produce good products and I guess that was my point.
I’d go with a Rhinehart block or the 18-1 target. To me they aren’t a pain to carry in the back of a vehicle and you’re getting a full size target. At one time they made a little target just for shooting a crossbow at the end of a hunt but to me you’re getting a lot more versatility out of the full size target.