Honestly, taking a hiatus is fine, but don't use your hiatus time completely for "bonus strips". One or two is fine (especially for things like tipping comics where you'd probably upload one eventually) but if you start releasing just concept art and stuff that you're working on "behind the scenes" (unless it was made long beforehand, in which case, fine), all that does is tell your readers "Hey, here's all this BoNuS MaTeRiAl that I took the time to work on, time that I could have used to actually work on the comic!" I mean, a bonus episode now and then is great, but unless you're paying for that stuff on Patreon (in which you're getting both bonus material and new updates at the same time), it's really not that great after several episodes of that sort of thing with no actual comic updates. At that point, you'd be better off just making your readers wait for another update for a few weeks IMO. It's a recurring trend with creators and it can cause more actual backlash than if you just took a break (which most, if not all people understand).
That's just some advice from someone who's dealt with that before (from both sides, as a creator and a reader). Other than that, taking a hiatus is totally fine and I'd definitely upload a tipping comic at the very least (I still have to do that for my own comics lol)